The Dictionary of Scientific Biography (DSB, 18 vols), is supplemented by The New DSB, which includes 7 vols. of additional entries and revised versions of some articles. Both sets are available in the Reading Room, and in the Main Library Reference area. The easiest way to access them is online – search the library catalog for the Complete Dictionary of Scientific Biography and you can access both sets integrated in digital form.
Online library catalog: http://libraries.ou.edu/
Catalog link to the Complete DSB (log in to the library website first, if you are off-campus).