-. (1989). Nature's wonderlands: National park of the world. National geography society.
Chicagoスタイル(17版)引用形式-. Nature's Wonderlands: National Park of the World. Washington: National geography society, 1989.
MLA(9版)引用形式-. Nature's Wonderlands: National Park of the World. National geography society, 1989.
警告: この引用は必ずしも正確ではありません.