Drooyan, I., & Hadel, W. (1964). A programmed introduction to number systems. Wiley.
芝加哥风格引文Drooyan, Irving, 与 Walter Hadel. A Programmed Introduction to Number Systems. New York: Wiley, 1964.
MLA引文Drooyan, Irving, 与 Walter Hadel. A Programmed Introduction to Number Systems. Wiley, 1964.
警告：这些引文格式不一定是100％准确.