Spring, I., & Manning, H. (1974). Wilderness trails Northwest: A hiker's and climber's overview-guide to national parks and wilderness areas in Wyoming, Montana, Idaho, Northern California, Oregon, Washington, British Columbia, Canadian Rockies. Touchstone Press.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)Spring, Ira, và Harvey Manning. Wilderness Trails Northwest: A Hiker's and Climber's Overview-guide to National Parks and Wilderness Areas in Wyoming, Montana, Idaho, Northern California, Oregon, Washington, British Columbia, Canadian Rockies. Beaverton, Or.: Touchstone Press, 1974.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)Spring, Ira, và Harvey Manning. Wilderness Trails Northwest: A Hiker's and Climber's Overview-guide to National Parks and Wilderness Areas in Wyoming, Montana, Idaho, Northern California, Oregon, Washington, British Columbia, Canadian Rockies. Touchstone Press, 1974.