Secondary documents are items that are not indexed by Scopus, but are extracted from references lists for the items indexed by Scopus.
Many subject specialized databases provide times cited information. Below are some examples. See the Databases by Subject listings to check and see if a database in your discipline offers times cited information.
Relative Citation Ratio (RCR) is a new metric that quantifies and compares the influence of a scientific article.
"... it works by counting an article’s network of citations, then weighting the result by using a comparison group within the article’s field. The developers of relative citation ratio said its methodology therefore better reflects how experts assess the influence of a paper, rather than just its total number of citations.” Chronicle of Higher Education Sept. 7, 2016