Não informado. (1966). Index to selected outdoor recreation literature. U.S. Department of the Interior, Bureau of Outdoor Recreation.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Index to Selected Outdoor Recreation Literature. Washington: U.S. Department of the Interior, Bureau of Outdoor Recreation, 1966.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Index to Selected Outdoor Recreation Literature. U.S. Department of the Interior, Bureau of Outdoor Recreation, 1966.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.