Perry, J., & Perry, J. G. (1988). The Sierra Club guide to the natural areas of Idaho, Montana, and Wyoming. Sierra Club Books.
Cita Chicago Style (17a ed.)Perry, John, y Jane Greverus Perry. The Sierra Club Guide to the Natural Areas of Idaho, Montana, and Wyoming. San Francisco: Sierra Club Books, 1988.
Cita MLA (8a ed.)Perry, John, y Jane Greverus Perry. The Sierra Club Guide to the Natural Areas of Idaho, Montana, and Wyoming. Sierra Club Books, 1988.
Precaución: Estas citas no son 100% exactas.