Office files of two former heads of the Columbia University Libraries' Reference Department. The files of Isadore Mudge, 1930-1937, 1940, and those of Constance M. Winchell, 1940-1945 and 1947-1959. The files are chiefly inter-office memoranda with other librarians and administrative memoranda for the department. There is some correspondence. Also, a file of Reference Department annual reports, 1904-1940.