APA
(1987). Window on America : Discovering Her Natural Beauty / Prepared by the Special Publications Division, National Geographic Society. : Washington, D.C. : The National Geographic Society, cop.
Chicago
1987. Window on America : Discovering Her Natural Beauty / Prepared by the Special Publications Division, National Geographic Society. : Washington, D.C. : The National Geographic Society, cop.
Harvard
(1987). Window on America : Discovering Her Natural Beauty / Prepared by the Special Publications Division, National Geographic Society. : Washington, D.C. : The National Geographic Society, cop.
MLA
Window on America : Discovering Her Natural Beauty / Prepared by the Special Publications Division, National Geographic Society. : Washington, D.C. : The National Geographic Society, cop. 1987.