APA引文

(1981). World English: Workbook. Washington, DC.: United states Department of state.

Trích dẫn kiểu Chicago

World English: Workbook. Washington, DC.: United states Department of state, 1981.

MLA引文

World English: Workbook. Washington, DC.: United states Department of state, 1981.

警告：这些引文格式不一定是100％准确.