Singh, Y. P. (1973). Key-communicators of agricultural innovations. Satish Book Enterprise.
Lua i Stíl Chicago (17ú heag.)Singh, Yogendra Pal. Key-communicators of Agricultural Innovations. Agra: Satish Book Enterprise, 1973.
Lua MLA (8ú heag.)Singh, Yogendra Pal. Key-communicators of Agricultural Innovations. Satish Book Enterprise, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.