APA Style

BALEN, B, V. (1991). Ornithological survey of the Kampar and Rokan rivers and their adjacent forests, Riau, Sumatra . : Asian Wetland Bureau-Indonesia.

MLA Style

BALEN, Bas, Van. "Ornithological survey of the Kampar and Rokan rivers and their adjacent forests, Riau, Sumatra". : Asian Wetland Bureau-Indonesia, 1991. Electronic resources.