APA

P. H. DAVIS & J. CULLEN, .The identification of flowering plant families. : .

Chicago

P. H. DAVIS & J. CULLEN, .The identification of flowering plant families. : .

Harvard

P. H. DAVIS & J. CULLEN, .The identification of flowering plant families. : .

MLA

P. H. DAVIS & J. CULLEN, .: . .