Xia, Zhihong (May 1992). "The Existence of Noncollision Singularities in Newtonian Systems". Ann. Math. Second Series. 135 (3): 411–468. doi:10.2307/2946572. JSTOR2946572.
Xia, Zhihong (May 1992). "The Existence of Noncollision Singularities in Newtonian Systems". Ann. Math. Second Series. 135 (3): 411–468. doi:10.2307/2946572. JSTOR2946572.