Singh, Y. P. (1973). Key-communicators of agricultural innovations. Satish Book Enterprise.
Chicago-viite (17. p.)Singh, Yogendra Pal. Key-communicators of Agricultural Innovations. Agra: Satish Book Enterprise, 1973.
MLA-viite (8. p.)Singh, Yogendra Pal. Key-communicators of Agricultural Innovations. Satish Book Enterprise, 1973.
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