APA aipamena

Blokhuis, W. A. (1993). Vertisols in the central clay plain of the Sudan. s.n..

Chicago Style aipamena

Blokhuis, W. A. Vertisols in the Central Clay Plain of the Sudan. [Netherlands?: s.n., 1993.

MLA aipamena

Blokhuis, W. A. Vertisols in the Central Clay Plain of the Sudan. s.n., 1993.