Blichfeldt, H. F. (1896–1897). "On Triangles with Rational Sides and Having Rational Areas". Annals of Mathematics. 11 (1/6): 57–60. doi:10.2307/1967214. JSTOR1967214.
Blichfeldt, H. F. (1896–1897). "On Triangles with Rational Sides and Having Rational Areas". Annals of Mathematics. 11 (1/6): 57–60. doi:10.2307/1967214. JSTOR1967214.