Citation tracking / Citation-based search methods

The following figure b from (3) shows the difference between "indirect citation tracking" and "direct" on the timeline. Both the "co-citing references", which share at least one "cited reference" with the "seed reference" (the more the more important), and the "co-cited references", which are cited more frequently with the "seed paper", can lie before or after the "seed reference".

In Web of Science Core Collection, "References", "Citations" (cited by, forward) and "Related records" (co-citing references) are linked for each hit, see screenshot. The following explanation is displayed via the ?-icon next to "Related records":
"View a list of records that cite at least one document cited by the parent record identified at the top of the page. Related Records are ranked according to the number of references they share with the parent record.
The assumption behind Related Records searching is that articles that cite the same works have a subject relationship, regardless of whether their titles, abstracts, or keywords contain the same terms. The more cited references two articles share, the closer the subject relationship."

The second screenshot shows a random example of the descending sorting based on the "shared" references.

Connected Papers' "similarity metric is based on the concepts of Co-citation and Bibliographic Coupling." (https://www.connectedpapers.com/about). Both methods of indirect citation tracking are therefore used. According to a co-founder, the algorithm is "mostly based on graph theory". Semantic Scholar is used as the data basis. 5 "graphs" per month are free after registration, unlimited with the Academic option from around 4.50 euros per month.

After selecting a paper ("Search by keywords, paper title, DOI or another identifier"), 40 similar papers are displayed as a "graph" (grid with dots) or list (see screenshot), "Prior works" ("These are papers that were most commonly cited by the papers in the graph.") and "Derivative works" ("These are papers that cited many of the papers in the graph.") are available as additional options. For reference management programmes, .bib files (BibTeX) can be downloaded for each function.