Most Frequent Indicators

Citation Frequency The citation frequency indicates how often a publication has been cited in other scholarly/scientific publications.
Impact Factor Indicates how frequently a journal is cited on average (for details of how it is calculated, see Wikipedia).
h-index The h-index represents the number X of publications by a scholar or scientist that have been cited at least X times (for details of how it is calculated, see Wikipedia).
Altmetrics Metrics based on the machine analysis of modern forms of communication in relation to individual articles (see Altmetrics).

None of these indicators is adequate to assess the quality of scholarly or scientific output. They simply give an idea of the measurable aspects of scholarly and scientific activity.

Databases Providing Bibliometric Data (Selection)

Given differences in the database, the figures for the bibliometric indicators from the various providers are not identical.