Morris, J. W., & Freeman, O. W. (1972). World geography (3d ed.). McGraw-Hill.
芝加哥风格引文Morris, John W., 与 Otis Willard Freeman. World Geography. 3d ed. New York: McGraw-Hill, 1972.
MLA引文Morris, John W., 与 Otis Willard Freeman. World Geography. 3d ed. McGraw-Hill, 1972.
警告:这些引文格式不一定是100%准确.