Occasional paper.

APA Citation

Institute of Tropical Forestry (Río Piedras, S. Juan. (1942). Occasional paper. [Rio Piedras?: s.n.].

MLA Citation

Institute of Tropical Forestry (Río Piedras, San Juan, P.R.). Occasional Paper. [Rio Piedras?: s.n.], 1942.

Warning: These citations may not always be complete (especially for serials).