KELTNER, A. (1981). English for adult competency 1. Prentice-Hall.
芝加哥风格引文KELTNER, Autumn. English for Adult Competency 1. New Jersey: Prentice-Hall, 1981.
MLA引文KELTNER, Autumn. English for Adult Competency 1. Prentice-Hall, 1981.
警告：这些引文格式不一定是100％准确.