Ledbetter, D. A. (1969). Elementary college arithmetic. Goodyear Publishing Company, Inc.
芝加哥风格引文Ledbetter, David A. Elementary College Arithmetic. Pacific Palisades,California: Goodyear Publishing Company, Inc, 1969.
MLA引文Ledbetter, David A. Elementary College Arithmetic. Goodyear Publishing Company, Inc, 1969.
警告：这些引文格式不一定是100％准确.