APA Style

Royen, P, V. (1957). Revision of the Sapotaceae of the Malaysian Area ina Wider Sense VII. Planchonella Pierre . Leiden: Blumea.

MLA Style

Royen, P., Van. "Revision of the Sapotaceae of the Malaysian Area ina Wider Sense VII. Planchonella Pierre". Leiden: Blumea, 1957. Text.