Schaefer, R. T. (1990). Racial and ethnic groups (4th ed.). Harper Collins.
芝加哥风格引文Schaefer, Richard T. Racial and Ethnic Groups. 4th ed. USA: Harper Collins, 1990.
MLA引文Schaefer, Richard T. Racial and Ethnic Groups. 4th ed. Harper Collins, 1990.
警告：这些引文格式不一定是100％准确.