Kharakhanian, I.M. (2002) β€œON THE EQUATION ${\bf{\it h}}x-x{\bf{\it k}}=c$ IN BANACH ALGEBRA ${\bf{\it A}}$, WITH HERMITIAN COEFFICIENTS ${\bf{\it h}}, {\bf{\it k}}$”, Proceedings of the YSU A: Physical and Mathematical Sciences, 36(1 (197), pp. 3–8. doi:10.46991/PYSUA.2002.36.1.003.