Alcala, A. (2008). Agusan River estuary development potential. Malaya.
Chicagoスタイル(17版)引用形式Alcala, Angel. "Agusan River Estuary Development Potential." Malaya 2008.
MLA(9版)引用形式Alcala, Angel. "Agusan River Estuary Development Potential." Malaya, 2008.
警告: この引用は必ずしも正確ではありません.