Castillo, G. T. (1995). Secondary crops in primary functions: The search for systems, synergy, and sustainability. UPWARD.
Chicago-viite (17. p.)Castillo, Gelia T. Secondary Crops in Primary Functions: The Search for Systems, Synergy, and Sustainability. Los Banos, Laguna: UPWARD, 1995.
MLA-viite (9. p.)Castillo, Gelia T. Secondary Crops in Primary Functions: The Search for Systems, Synergy, and Sustainability. UPWARD, 1995.
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