Eko, E. E. (1999). Effective writing. Heinemann Educational Books.
芝加哥风格引文Eko, Ebele E. Effective Writing. Heinemann Educational Books, 1999.
MLA引文Eko, Ebele E. Effective Writing. Heinemann Educational Books, 1999.
警告：这些引文格式不一定是100％准确.
APA引文