Proceedings of the fourth International Congress of Phonetic Sciences : held at the University of Helsinki 4-9 September 1961 - Sovijärvi, Antti, 1912-1995; Aalto, Pentti, 1917-1998 (Janua Linguarum. Studia memoriae Nicolai van Wijk Dedicata. Studia memoriae Nicolai van Wijk Dedicata. Series Maior ;, 1962)