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.
Bremner et al. (1983) "Loss of circadian rhythmicity in blood testosterone levels with aging in normal men." J. Clin. Endocrinol. Metab. 56(6):1278-1281 (PubMed)