Agricultural extension in the developing countries : A bibliography
de Vries, C.A.
Agricultural extension in the developing countries : A bibliography - Wageningen 1968 - No. 7; Netherlands Internation .
016:63(071.7)(1-77)
Agricultural extension in the developing countries : A bibliography - Wageningen 1968 - No. 7; Netherlands Internation .
016:63(071.7)(1-77)