International Conference of Agricultural Economists & International Association of Agricultural Economists. (1956). Proceedings of the ninth International Conference of Agricultural Economists. oxford university press.

International Conference of Agricultural Economists and International Association of Agricultural Economists. Proceedings of the Ninth International Conference of Agricultural Economists. new York: oxford university press, 1956.

International Conference of Agricultural Economists and International Association of Agricultural Economists. Proceedings of the Ninth International Conference of Agricultural Economists. oxford university press, 1956.