1. D. M. Bushev, "Isometry of functional spaces with different number of variables," Ukr. Mat. Zh., 50, No. 8, 1027-1045 (1998)
2. English translation:Ukr. Math. J., 50, No. 8, 1170-1191 (1998).
3. D. M. Bushev and Yu. I. Kharkevych, "Conditions of convergence almost everywhere for the convolution of a function with deltashaped kernel to this function," Ukr. Mat. Zh., 67, No. 11, 1461-1476 (2015)
4. English translation:Ukr. Math. J., 67, No. 11, 1643-1661 (2016).
5. D. N. Bushev and Yu. I. Kharkevich, “Determination of the subspaces of solutions of the Laplace and heat-conduction equations isometric to the spaces of real functions and some their applications,” Mat. Zametki, 103, No. 6, 803–817 (2018).