International Congres voor Doffstommenzorg = International Congress on the Care of the Deaf-mute = Congès International concernant les sourds-muets = Internationaler Kongress für Taubstummenfür sorge, Groningen, 5-10 Juni 1950.
International Congress on the Care of the Deaf-mute (1950 : Groningen, Netherlands) | Date: [1950]