APA

Opler P. A., Baker H. G. & Frankie G. W.Comparative phenological studies of treelet and shrub species in tropical wet and dry forests in the Lowlands of Costa Rica. : .

Chicago

Opler Paul A, Baker Herbert G and Frankie Gordon W.Comparative phenological studies of treelet and shrub species in tropical wet and dry forests in the Lowlands of Costa Rica. : .

Harvard

Opler P. A., Baker H. G. and Frankie G. W.Comparative phenological studies of treelet and shrub species in tropical wet and dry forests in the Lowlands of Costa Rica. : .

MLA

Opler Paul A, Baker Herbert G and Frankie Gordon W.: . .