Não informado. (1966). Index to selected outdoor recreation literature. U.S. Department of the Interior, Bureau of Outdoor Recreation.
Chicago-viite (17. p.)Não informado. Index to Selected Outdoor Recreation Literature. Washington: U.S. Department of the Interior, Bureau of Outdoor Recreation, 1966.
MLA-viite (8. p.)Não informado. Index to Selected Outdoor Recreation Literature. U.S. Department of the Interior, Bureau of Outdoor Recreation, 1966.
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