Sometimes articles in Litmaps display a lower number of references and/or citations than an article is expected to have. This can be for several reasons:
The first, and more probable reason, is that those references/citations don't have open access metadata. We're legally only able to index open access metadata, so we can't represent any citations/references that don't have this supplied. We're actively working on ways to better represent un-indexed references and citations within Litmaps.
Some newer articles may have a delay in their citations and references appearing.
Citations of older articles by very recent articles may similarly have a delay before appearing.
We may be displaying a version of the article which has poor citation information: see Our Database: How do you handle article versioning. While we try our best to select the highest-quality data source, sometimes errors can slip in.
For more, see Our Database