Singh, I. P., & Tiwari, S. C. (1980). Man and his environment. Concept.
Lua i Stíl Chicago (17ú heag.)Singh, Indera P., agus Surendra Chandra Tiwari. Man and His Environment. New Delhi: Concept, 1980.
Lua MLA (8ú heag.)Singh, Indera P., agus Surendra Chandra Tiwari. Man and His Environment. Concept, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.