Journal rankings are based on bibliometrics, which is a set of quantitative methods used :
to measure patterns of scientific publication and citation
to assess the impact of research
A list of top journals will differ depending on citation tools, metrics chosen for analysis and how broadly a field is defined. Journal rankings may change from year to year.
The standard source for journal rankings is the Journal Citation Reports (JCR) from the ISI Web of Knowledge by Thomson Reuters.
Author Impact Factor
The h-index quantifies the actual scientific productivity and the apparent impact of the scientist. The h-index is based on the author’s most cited papers and the number of citations they have received from other articles.
Cited Reference is the number which indicates the number of times the reference has been cited.
In a Web of Science/Knowledge Search:
Enter your search term, note your results and number of cited times
Click on item title (Lessons from Russia - A newo-authoritarian media system) to view Impact Factor for the Journal.
Interpretation of data below:
The 2014 Impact Factor for the European Journal of Communication is 1.088 thus, the journal ranks 29th (out of 76 journals, Q2 quartile) in the subject category COMMUNICATION.
Impact Factor and Rank for a Journal
Use the Journal Citation Reports (JCR) to locate impact factors. The impact factor is a measure of the frequency with which the average article in a journal has been cited in a particular year. The JCR also lists journals and their impact factors and ranking in the context of their specific field(s).
Journal Citation Ranking and Quartile Scores
Based on Impact Factor (IF) data, the Journal Citation Reports published by Thomson Reuters provides yearly rankings of science and social science journals, in the subject categories relevant for the journal (in fact, there may be more than one).
Quartile rankings are derived for each journal in each of its subject categories according to which quartile of the IF distribution the journal occupies for that subject category.
Q1 denotes the top 25% of the IF distribution
Q2 for middle-high position (between top 50% and top 25%)
Q3 middle-low position (top 75% to top 50%)
Q4 the lowest position (bottom 25% of the IF distribution)
Google Scholar "Cited References"
Google Scholar (GS) covers scholarly literatures from all broad areas of research. Each Google Scholar search result contains bibliographic information, such as the title, author names, and source of publication. At the end of the search result is a “Cited by” link, which will display a list of articles and documents that have cited the document originally retrieved in the search. Note that this only includes resources indexed by Google Scholar.
How to find Cited References in Google Scholar:
Go to Google Scholar
Enter search terms, such as an individual author or a particular article citation
Look for the “Cited by” link at the bottom of the citation
Click on the “Cited by” link to retrieve citations to the original resource
Limitations of Google Scholar Cited References
GS includes some non-scholarly citations
It is not clear exactly which scholarly resources are included in GS
GS does not perform well for older publications
GS is a beta product and may change at any time
GS is not updated as often as WoS
GS may find the same citing work more than once and count them more than once in its total. It's important to go through the list of citing works to remove duplicates.