"Manipulating Google Scholar Citations and Google Scholar Metrics: simple, easy and tempting" Delgado-López-Cózar, Emilio; Cabezas-Clavijo, Álvaro. 2012.
“Google Scholar Metrics: an unreliable tool for assessing scientific journals” Delgado-López-Cózar, Emilio; Cabezas-Clavijo, Álvaro. El profesional de la información, 2012.
"Google's Book Search: A Disaster for Scholars" Geoffrey Nunberg, Chronicle of Higher Ed, 2009.
Since it is difficult to know which publications and dates are in Google Scholar, and because of serious errors in its counts (see "Limitations" below) results in Google Scholar must be carefully examined and it should only be used as a supplement to other tools.
Look for the link to "Cited By" which will identify works that have cited the document originally retrieved in the search. Be certain to examine the cited works themselves to eliminate duplicate counts (some cited by citations are listed and counted more than once) and other errors.
Alternatively, Google Scholar Citations allows authors to set up their own profile, which is automatically updated, and which is more manageable and possibly less labor than searching by author or article title.
There are arguments in the literature as to whether or not Google Scholar is a better citation tracker than ISI Thomson Reuters products, e.g., Web of Science. This guide concludes that it is not, that it is less accurate and less reliable. For those looking for a cost-free alternative to ISI products, this guides recommends Microsoft Academic Search.
NOTE: Due to its popularity, it is important to note that there are potentially important problems with using Google Scholar as a citation analysis tool. Here are a few:
Many of these problems and more are replicated at the level of journal evaluation.
To get a count of journal articles that appear in books is unusual among citation tools and particularly relevant to Humanities and Social Sciences. Google Books can be used to find citations within books to articles in journals. This may very usefully supplement counts of article citations that appear in other articles.
Use the “Advanced Book Search” and enter the full title of the article in “with the exact phrase.” Across from “Search” keep the default at “all books.” Change the default of “Content” to “books” only.