Fourth international environmental congress program, 640 - 30 - 001, Folder: Archives 640-30-001. Clarion University Archives.
Fourth international environmental congress program, 640 - 30 - 001, Folder: Archives 640-30-001. Clarion University Archives. http://as-clarion.klnpa.org/repositories/2/resources/1195 Accessed January 14, 2026.