International yearbook of education, Vol. XXX, 1968.
International yearbook of education, Vol. XXX, 1968.
- Geneva : Paris, IBE, UNESCO, 1969.
- 566 p.
- IBE publication ; 322. .
OC 37 (100) =20 "1968" INN Vol. 30
OC 37 (100) =20 "1968" INN Vol. 30