Contains records kept by Cora Sanders (1872-1964), the Clark's curator and librarian from the 1910s to 1943, including ledgers, acquisition records and bibliographic records, as well as some personal materials. Sanders was originally employed as secretary to Mr Clark's two wives and then as his secretary and assistant, after their respective deaths. Though not formally trained as a librarian or bibliographer, Sanders learned the necessary skills through her exposure to the collections, and after Mr Clark's death in 1934, worked for UCLA as Curator of collections until 1943.