Connecting literature with objects

For finding who is indexing the scientific objects for literature, I conducted a random search. Here are some preliminary results.

        NASA ADS did the  closest work for indexing the astronomical objects from literature and explicitly associating literature with objects in its content page.

        PubMed integrate several databases, including genome and protein databases. Users can search genetic names in the literature search. However, no explicit link exist to connect literature with genomes or proteins.

        The MGI's Gene Expression Literature database, which is hosted by the Jackson Laboratory, has an interesting search function, which indexes literature in their database with genetic experssion. Hence each biblio-record has a link refering to genetic object.

So far, I didn't find clear statement about how they indexing this objects. But it seems that specific databases do start to index scientific objects to literature and build up the connection for research.