Cita APA

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

Chicago Style (17th ed.) Citation

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

Cita MLA

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