APA (7e ed.) Bronvermelding

Preston, R. J. (1968). Rocky mountain trees: A handbook of the native species with plates and distributions maps (3a. ed.). Dover.

Chicago (17e ed.) Bronvermelding

Preston, Richard J. Rocky Mountain Trees: A Handbook of the Native Species with Plates and Distributions Maps. 3a. ed. Nueva York: Dover, 1968.

MLA (9e ed.) Bronvermelding

Preston, Richard J. Rocky Mountain Trees: A Handbook of the Native Species with Plates and Distributions Maps. 3a. ed. Dover, 1968.