Mikhailov, I. I.:
Об одном свойстве фигурных чисел.
(Russian) [A property of figurate numbers].Mathematica Slovaca,
vol. 33
(1983),
issue 3,
pp. 303-306
Mikhailov, I. I.:
Об уравнении $t_{x}+y^{2}=t_{z}+u^{2}$.
(Russian) [On the equation $t_{x}+y^{2}=t_{z}+u^{2}$].Mathematica Slovaca,
vol. 33
(1983),
issue 1,
pp. 35-39