LEFFINGWELL RICHARD. (2019). BASIC MATH DOUBLING AND MUTIPLYING (2018 Ed.). HEINEMANN LIBRARY.
芝加哥风格引文LEFFINGWELL RICHARD. BASIC MATH DOUBLING AND MUTIPLYING. 2018 Ed. MINNESOTA: HEINEMANN LIBRARY, 2019.
MLA引文LEFFINGWELL RICHARD. BASIC MATH DOUBLING AND MUTIPLYING. 2018 Ed. HEINEMANN LIBRARY, 2019.
警告：这些引文格式不一定是100％准确.