Global Change 
Sources of Information & Citation Guide 



Finding Relevant Sources of Information

There are many different individuals and organizations who discuss Global Change and sustainability. One of the goals of this course is that you should learn to think critically about all of these sources and for you to be able to deal with multiple, sometimes conflicting, notions about the impact and meaning of global change.

In order to achieve this goal, we want you to be very careful about the sources that you select for your research paper and your web project. You should be aware of the different classes of sources that you might encounter. The goal for your paper should be to select the most authoritative sources possible. Talk with your GSI if you have any questions. Some of the following types of sources are accessible through the library's Networked Electronic Resources webpage.

Newspapers and Mainstream Media (i.e. Detroit News, Ann Arbor News, New York Times, Time, Newsweek, AP, Reuters): Articles in these publications are usually written by journalists with no prior expertise in Global Change. Therefore the articles usually paraphrase their original sources and the authors often have no way to make a serious analysis of the material they are presented with. These sources are therefore, not very authoritative.

Peer-reviewed scientific journals (i.e. Science, Nature): These articles are usually written by the individuals doing the original experiments or data collection. Also, these articles must be approved by scientific peers before they can be published. Therefore, while articles in these venues may not be perfect, and should be subjected to a critical reading, they have been "approved" by more than one member of the scientific community and are highly authoritative.

Scientifically related magazines and journals (i.e. Scientific American): These articles are usually not peer-reviewed, but are typically written by scientists doing original research or by journalists with a high degree of familiarity with the material. 

Advocacy publications (i.e. Sierra Club, Nature Conservancy, World Wildlife Fund, Political Parties) : These groups have no real motivation to present complete research and tell the "whole story." Therefore, you should use their information with caution and approach it critically. Some of the material (i.e. research articles in Nature Conservancy magazines) is excellent and is written by scientists using the same standards they would use to write a peer-reviewed article, other material is only designed to change minds and uses information highly selectively. 

Web-based publications: These vary considerably. Many of the peer-reviewed magazines and journals have web-based counterparts (i.e., that are held to the same high standards. There are also government information web-sites (,, that have excellent data. However, you should be careful about using random web pages found during a search with unknown authors and unknown quality.

Citing Sources

There are several reasons why we cite the work of others in term papers and scientific papers. We need to give credit to the work of others, add authority to our statements or claims (e.g., we aren’t just making this up – someone did a careful study), and be honest about our own contribution and role.  Any substantial claim or argument that you make, if it evolved directly out of your reading of the works of others, should be cited. The specific citation "styles" for different publications are explained below with examples, and in the next section we discuss more fully the issue of when to make a citation.

A perennial problem we all face is how much to paraphrase, or to rearrange the words of others, in something that we write.  Often the original author stated the case well, so, why re-word it?  You can keep the exact wording, but if you quote a sentence or paragraph directly, put that material in quotes, and add the citation (usually you "offset" the quote as well).

        "The rain in Spain makes a stain" (Jones 1937).

Most of the time, however, you will re-word the original material as you blend it into your own writing style. In this case skip the quotation marks but keep the citation.  For example, your sentence might read "As Jones (1937) has pointed out, precipitation in Spain may leave a mark", or, "Stains often are encountered in Spain after rain (Jones 1937)".  No sensible essay is simply a string of quotes, so re-structuring of source material is common.

What if you repeat a few words or a phrase?  This is a gray area.  In scientific writing, which puts a premium on a concise style, there may be only so many ways to say the same basic idea.  Don't worry about "using" a few similar words if they are largely embedded in your own sentence, and of course you still must cite Jones (1937).

Finally and regrettably, there is intentional plagiarism. When someone uses a large amount of material, word-for-word, from another source and does not cite the source, they are presenting someone else's work as their own. This is a serious offense (it can be thought of as identity theft), and it can get you tossed out of this University.  In the professional world plagiarism is rare, but it can be common in situations where people don't know any better and are not educated about the issue; this is why you are reading this Guide. One thing to remember is that experienced graders (e.g., GSIs) can spot plagiarism quickly. Just as you found the material you are using on the web, web search engines will easily identify key phrases found in the original source (that you did not cite...). If you have any questions about when to cite other works, ask your classmates, and if you all disagree then ask your GSI or professor.

Citation Style Examples

You should follow the style examples given below exactly in your written work in this class. Note that there are many different nuances of citation style for a complete reference, and in fact each scientific or literary journal will require you to use a specific style. However, each style still conveys the important information, and for consistency and easy preparation for your papers in this class you must follow these examples below. [Note that the situation of the citation is given in brackets after the example.]

In citing the reference in brief in the text of your paper, use the following style conventions for single, double, and multiple authors, for multiple references, and for web references (all references are taken from the style examples at the bottom of this guide):

1. Climate change is affecting sea level in the Baltic (Andersson 2002), and it may become a problem especially as nutrient levels and eutrophication increase (Conley et al., 2009). Such changes may impact many different aspects of water chemistry (Stumm and Morgan 1981).

2. Andersson (2002) reports that sea level in the Baltic is changing due to climate, and Conley et al. (2009) report that eutrophication may also become a problem.

3. Changes in the Baltic sea include both climate change and eutrophication (Andersson 2002; Conley et al., 2009). On the other side of the world, and on land, the Emerald Ash Borer has become an economically important problem (Emerald Ash Borer 2007).


Andersson, H.C. 2002. Influence of long-term regional and large-scale atmospheric circulation on the Baltic sea level. Tellus A 54: 76-88. [single author - "54" is the issue or volume of the journal, and "76-88" are the page numbers.]

Bryant, P.J., and P. Simpson. 1984. Intrinsic and extrinsic control of growth in developing organs. Quart. Rev. Biol. 59: 387-415. [two authors]

Conley, D.J., H.W. Paerl, R.W. Howarth, D.F. Boesch, S.P. Seitzinger, K.E. Havens, C. Lancelot, and G.E. Likens. 2009. Controlling eutrophication: Nitrogen and phosphorus. Science 323: 1014-1015. [multiple authors].

In recent years publications are given a Digital Object Identifier (DOI), which is a unique tag for that publication. Thus, a paper with a DOI may also contain page numbers, and at least one of these is needed to complete the reference. For example, if there are page numbers and a DOI the citation would be as follows:

De Pol-Holz, R., O. Ulloa, L. Dezileau, J. Kaiser, F. Lamy, and D. Hebbeln. 2006. Melting of the patagonian ice sheet and deglacial perturbations of the nitrogen cycle in the eastern South Pacific. Geophys. Res. Lett. 33: 15-32, doi:10.1029/2005GL024477.

You can check that every DOI that you cite is correct via the doi system website.


Stumm, W., and J. Morgan. 1981. Aquatic chemistry, 2nd ed. Wiley.

National Academy of Sciences. 1977. Principles and Procedures for Evaluating the Toxicity of Household Substances. National Academy of Sciences, Washington, DC. [here the organization is both the author and publisher]

Chapter in a book:

Codispoti, L.A. 1983. Nitrogen in upwelling systems, p. 513-564. In E. J. Carpenter and D. G. Capone [eds.], Nitrogen in the marine environment. Academic Press.


Kimmance, S.A. 2001. The interactive effect of temperature and food concentration on plankton grazing and growth rates. Ph.D. thesis. Univ. of Liverpool.

Technical reports

Shaw,G. B. 1982. "Practical uses of litmus paper in Möbius strips". Tech. Rep. CUCS-29-82, Columbia Univ., New York.

Lassiter, R. R., and J.L. Cooley. 1983. Prediction of ecological effects of toxic chemicals, overall strategy and theoretical basis for the ecosystem model. EPA-600/3-83-084. National Technical Information Service PB 83-261-685, Springfield, VA.

Press, F. 1981. "A report on the computational needs for physics". National Science Foundation, Washington, DC. [unpublished work]

"Assessment of the carcinogenicity and mutagenicity of chemicals". 1974. WHO Tech. Rep. Ser. No. 556. [no author]

Preprints (articles currently being published but not yet in print)

Smette, A., et al. In Press. HST/STIS observations of the HeII Gunn-Peterson effect towards HE 2347-4342. Astrophys. Journal (available at [if now published, omit the URL and provide only a standard reference]

Paper presented at a meeting (not published)

Konishi, M. 1984. Paper presented at the 14th Annual Meeting of the Society for Neuroscience, Anaheim, CA, 10 October 1984. [Here you need to include the sponsoring organization if it is not part of the meeting name, and the title of the paper if it was listed]

Newspaper article:
Bishop, J.E. 1982. Do flies spread ills or is that claim merely a bugaboo? The Wall Street Journal. Nov. 1982, 4:1 (col. 4), 23 (col. 1).

Personal communications

G. Reuter, personal communication, 15 November 2009.

Citing Web Sources:
Below are some general rules and examples on citing web sources, modified from:

net.Tutor, © 1997-2009, The Ohio State University Libraries. Available from: (Site visited on 15 November 2009)

  • Provide sufficient information to allow a reader to locate the source you are citing.
  • Web documents share many elements found in print sources. The citation for a Web document often follows a format similar to that for print, with some information omitted and some added. Always cite the original print document rather than the web retrieval address.
  • Cite what is available when you cannot find some elements of information about a source. For example, publication dates may not be provided for some online information sources. If the work originally had a print existence, it may be necesssary to give the date of the original print publication.
  • Include the date that you accessed the source (when required by the style manual).
  • Cite the address (URL) accurately. If it is necessary to divide the URL between two lines, break only after a slash mark and do not insert a hyphen at the break.

Hilton-Taylor C., compiler. 2000. 2000 IUCN red list of threatened species [Internet]. Gland, Switzerland and Cambridge, UK: IUCN. Available from: (Site visited 12 Feb 2002) [web site with author]

Emerald Ash Borer (EAB), updated 2007 Feb 27. Columbus (OH): Ohio Department of Natural Resources, Division of Forestry. Available from: (Site visited 24 July 2007) [web site with no author]


Please ask your GSI if you need any clarifications.

All materials © 2009 by the Global Change Program, University of Michigan