Singh, S., & Wulf, D. H. (2009). Abortion worldwide: A decade of uneven progress.
芝加哥风格引文Singh, Susheela, 与 Deirdre Hussain Wulf. Abortion Worldwide: A Decade of Uneven Progress. 2009.
MLA引文Singh, Susheela, 与 Deirdre Hussain Wulf. Abortion Worldwide: A Decade of Uneven Progress. 2009.
警告：这些引文格式不一定是100％准确.