Walker, B. S. (1973). The great divide: The American wilderness - Time-Life books - Alexandria, Virginia. Time-Life Books.
Chicago-viite (17. p.)Walker, Bryce S. The Great Divide: The American Wilderness - Time-Life Books - Alexandria, Virginia. Estados Unidos: Time-Life Books, 1973.
MLA-viite (9. p.)Walker, Bryce S. The Great Divide: The American Wilderness - Time-Life Books - Alexandria, Virginia. Time-Life Books, 1973.
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