American Telephone and Telegraph Company. Department of Operation and Engineering. (1952). Engineering economy. Amer. Telephone and Telegraph Co..
芝加哥风格引文American Telephone and Telegraph Company. Department of Operation and Engineering. Engineering Economy. N.Y.: Amer. Telephone and Telegraph Co., 1952.
MLA引文American Telephone and Telegraph Company. Department of Operation and Engineering. Engineering Economy. Amer. Telephone and Telegraph Co., 1952.
警告：这些引文格式不一定是100％准确.