Simcha Brudno (1964). "A further example of A4 + B4 + C4 + D4 = E4". Mathematical Proceedings of the Cambridge Philosophical Society. 60 (4): 1027–1028. doi:10.1017/S0305004100038470. MR0166151.
Simcha Brudno (1964). "A further example of A4 + B4 + C4 + D4 = E4". Mathematical Proceedings of the Cambridge Philosophical Society. 60 (4): 1027–1028. doi:10.1017/S0305004100038470. MR0166151.