Knapp, B. J., McCrae, D., & Ross, S. (1989). Challenge of the natural environment. Longman.
芝加哥风格引文Knapp, Brian J., Duncan McCrae, 与 Simon Ross. Challenge of the Natural Environment. Harlow: Longman, 1989.
MLA引文Knapp, Brian J., et al. Challenge of the Natural Environment. Longman, 1989.
警告：这些引文格式不一定是100％准确.