APA

Little E. L., Woodbury R. o. & Wadsworth F. H. (1974). Trees of Puerto Rico and the Virgin Islands : second volume. Washington: United States Departament of Agriculture.

Chicago

Little Elbert L, Woodbury Roy o and Wadsworth Frank H. 1974. Trees of Puerto Rico and the Virgin Islands : second volume. Washington: United States Departament of Agriculture.

Harvard

Little E. L., Woodbury R. o. and Wadsworth F. H. (1974). Trees of Puerto Rico and the Virgin Islands : second volume. Washington: United States Departament of Agriculture.

MLA

Little Elbert L, Woodbury Roy o and Wadsworth Frank H. Trees of Puerto Rico and the Virgin Islands : second volume. Washington: United States Departament of Agriculture. 1974.