-
Bằng Spring, Ira
Được phát hành 1994 -
Nature in the Northwestan introduction to the natural history and ecology of the northwestern United States from the Rockies to the PacificBookBằng Schwartz, Susan H., 1946-
Được phát hành 1983 -
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 RockiesBookBằng Spring, Ira
Được phát hành 1974