Gerry Leversha & G. C. Smith (Kasım 2007), "Euler and Triangle Geometry", The Mathematical Gazette, 91 (522), ss. 436-452, doi:10.1017/S0025557200182087, JSTOR40378417
Gerry Leversha & G. C. Smith (Kasım 2007), "Euler and Triangle Geometry", The Mathematical Gazette, 91 (522), ss. 436-452, doi:10.1017/S0025557200182087, JSTOR40378417