Littell, M. (1994). Gateways to mathematical investigations (Teacher's ed.). McDougal,Littell & Co..
芝加哥风格引文Littell, McDougal. Gateways to Mathematical Investigations. Teacher's ed. Dallas: McDougal,Littell & Co., 1994.
MLA引文Littell, McDougal. Gateways to Mathematical Investigations. Teacher's ed. McDougal,Littell & Co., 1994.
警告：这些引文格式不一定是100％准确.