Keith-Lucas, A. (1972). Giving and taking help. University of North Carolina.
芝加哥风格引文Keith-Lucas, Alan. Giving and Taking Help. Chapel hill: University of North Carolina, 1972.
MLA引文Keith-Lucas, Alan. Giving and Taking Help. University of North Carolina, 1972.
警告：这些引文格式不一定是100％准确.