Opera is My Hobby - Marcello Alvarez (series VII, n. 720); Ivan Petrov (series VII, n. 720); Baritones at the Met 1900 - 1950 (series VII, n. 721); In Memoriam: Alain Vanzo (series VII, n. 722), Box: 12, Folder: 70. Personal Papers of James E. Seaver, PP 534. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/163715 Accessed June 21, 2025.