Havas, G., & Vaughan-Lee, M. (2005). 4-Engel groups are locally nilpotent.
芝加哥风格引文Havas, G., 与 M. Vaughan-Lee. 4-Engel Groups Are Locally Nilpotent. 2005.
MLA引文Havas, G., 与 M. Vaughan-Lee. 4-Engel Groups Are Locally Nilpotent. 2005.
警告：这些引文格式不一定是100％准确.