Harshberger, J. W. (1958). Phytogeographic survey of North America: A consideration of the phytogeography of the North American continent, including Mexico, Central America and the West Indies, together with the evolution of North American plant distribution (Nachdr. d. Ausg. Leipzig 1911, 2. Aufl.). Engelmann.
Chicago-Zitierstil (17. Ausg.)Harshberger, John William. Phytogeographic Survey of North America: A Consideration of the Phytogeography of the North American Continent, Including Mexico, Central America and the West Indies, Together with the Evolution of North American Plant Distribution. Nachdr. d. Ausg. Leipzig 1911, 2. Aufl. Weinheim/Bergstr: Engelmann, 1958.
MLA-Zitierstil (9. Ausg.)Harshberger, John William. Phytogeographic Survey of North America: A Consideration of the Phytogeography of the North American Continent, Including Mexico, Central America and the West Indies, Together with the Evolution of North American Plant Distribution. Nachdr. d. Ausg. Leipzig 1911, 2. Aufl. Engelmann, 1958.