Literature mining for the biologist: from information retrieval to biological discovery -- Nat. Rev. Genetics
Good review... but doesn't mention pubnet!
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16418747&query_hl=15&itool=pubmed_docsum
Nat Rev Genet. 2006 Feb;7(2):119-29.
Literature mining for the biologist: from information retrieval to biological discovery.Jensen LJ, Saric J, Bork P.