[S.J.] Thomas Zamarriego ed[itor] - Enciclopedia de Orientacion Bibliografica, 4 volumes, Barcelona: 1964, vol[ume] II, page 611-793

[S.J.] Thomas Zamarriego ed[itor] - Enciclopedia de Orientacion Bibliografica, 4 volumes, Barcelona: 1964, vol[ume] II, page 611-793, Box: 6, Folder: 37-44. Personal papers of Richard T. De George, PP 531. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/315169 Accessed December 24, 2025.