The Saint Louis University Libraries Catalog provides access to books and more. Searching can be expanded to include the MOBIUS consortium which includes most of the academic libraries in Missouri. Pius XII Memorial Library uses Library of Congress classification (call) numbers.
For instance, you can search by title - Human factors in aviation and get the book's call number TL553.6 .H86 2010
E-books are also searchable via the Library Catalog, for instance the title, Safety Culture, is available at this URL.
Another book of interest for budding pilots: 2013 private pilot test prep [electronic resource] : study and prepare for recreational and private: airplane, helicopter, gyroplane, glider, balloon, airship, powered parachute, and weight-shift control FAA knowledge exams. Grab it here.
If you cant' find the specific resource you need? Try WorldCat, the nation-wide library catalog.