STEP 1: CHECK WUSTL
WUSTL Catalog - Search for items and resources available at available at Washington university.
MOBIUS - Search cooperating Missouri libraries resources, which can be borrowed.
Worldcat - The catalog of the world's library holdings. Search for items which you were unable to locate via WUSTL or MOBIUS; the libraries can usually get access for you via interlibrary loan.
WU Medical Library - Search resources available at the Medical Library.