Sommers, J. W. (1965). Bibliography of African geography, 1940-1964. s. n.].
芝加哥风格引文Sommers, John W. Bibliography of African Geography, 1940-1964. [Hanover, N. H: s. n.], 1965.
MLA引文Sommers, John W. Bibliography of African Geography, 1940-1964. s. n.], 1965.
警告：这些引文格式不一定是100％准确.