Williams, I. A., & Allen, J. E. (1991). Geologic history of the Columbia River Gorge, as interpreted from the historic Columbia River scenic highway (3rd ed., rev.). Oregon Historical Society Press.
Цитирование в стиле Чикаго (17-е изд.)Williams, Ira A., и John Eliot Allen. Geologic History of the Columbia River Gorge, as Interpreted from the Historic Columbia River Scenic Highway. 3rd ed., rev. Portland, Or.: Oregon Historical Society Press, 1991.
Цитирование MLA (8-е изд.)Williams, Ira A., и John Eliot Allen. Geologic History of the Columbia River Gorge, as Interpreted from the Historic Columbia River Scenic Highway. 3rd ed., rev. Oregon Historical Society Press, 1991.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.