Leppan, H. D. (1928). The agricultural development of arid and semi-arid regions: With special reference to South Africa. Central News Agency.
Lua i Stíl Chicago (17ú heag.)Leppan, Hubert Dudley. The Agricultural Development of Arid and Semi-arid Regions: With Special Reference to South Africa. [Pretoria?] South Africa: Central News Agency, 1928.
Lua MLA (8ú heag.)Leppan, Hubert Dudley. The Agricultural Development of Arid and Semi-arid Regions: With Special Reference to South Africa. Central News Agency, 1928.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.