<p>1. Bivariate symmetry: definitions and basic properties<br/>Ibrahim A. Ahmad; Patricia B. Cerrito <br/>Journal of Nonparametric Statistics, Volume 1, Issue 1, 1991, Pages 165 – 169</p><p>2. some concepts of bivariate symmetry . </p><p>&nbsp; Nelsen. RB.&nbsp; Journal of Nonparametric Statistics, Volume 3, 1993, Pages 95 – 101.</p><p>谢谢！</p><p></p><p><a href="http://www.soudoc.com/webdisk/myfile/people/111.pdf">http://www.soudoc.com/webdisk/myfile/people/111.pdf</a></p><p><a href="http://www.soudoc.com/webdisk/myfile/people/222.pdf">http://www.soudoc.com/webdisk/myfile/people/222.pdf</a></p><p></p><p></p>