You can search for any reference by title, author, date, editor, journal and publisher. Searching is case insensitive, and allows for only partial terms (e.g. seq with pickup both RNA-Seq and sequencing) matching. You can also use advanced queries that are detailed here.
Weiskopf et al. (2009) "The aging of the immune system." Transpl. Int. 22(11):1041-1050 (PubMed)