Gary J. Clyman. "Sexual Kung Fu [ch. 8]". The Chi Kung Bible: Mastering Personal Power. Archived from the original on 2009-02-08. Retrieved 2008-07-08.
Gary J. Clyman. "Sexual Kung Fu [ch. 8]". The Chi Kung Bible: Mastering Personal Power. Archived from the original on 2009-02-08. Retrieved 2008-07-08.