A way to identify the impact of an article is to see how often the article has been cited. In general, the greater the amount of citations that an article attracts, the more significant this article is to the respective discipline.
To find out how often an article has been cited, you can use a database that provides "Time Cited" information which shows the number of times an article has been cited by other articles indexed in the same database. For example:
[from Web of Science]
The following Library-subscribed databases provide citation counts of articles:
You can also sort a result list retrieved from Web of Science & Scopus by "Time cited - highest to lowest" and "Citations" respectively to identify top papers on a topic.
Some search engines also allow you to locate information about the number of cites to articles. Examples are:
In addition to citation counts, you can also use other measures to identify the relative importance of an article. These alternative metrics are often referred to as "Article-Level Metrics", or "Altmetrics". For example:
Articles can also be evaluated using qualitative methods. For example: