Chen, Zhibo; Liang, Tian (2006). "The converse of Viviani's theorem". The College Mathematics Journal. 37 (5): 390–391. doi:10.2307/27646392. JSTOR27646392.
Chen, Zhibo; Liang, Tian (2006). "The converse of Viviani's theorem". The College Mathematics Journal. 37 (5): 390–391. doi:10.2307/27646392. JSTOR27646392.