XIANGCHEN L, YAXIN Y, YIPENG W, HEPING L, WEIJUN G, YUEHUI M. Effect of cryotop vitrification method on oocytes at different meiotic stages and embryo development in vitro. Indian J of Anim Sci. 2012;82(11):1311–1316. doi:10.56093/ijans.v82i11.25133