A.Sh. Shaldanbayev, M.B. Ivanova, A.N.Urmatova, и A.A. Shaldanbayeva. 2019. «SPECTRAL DECOMPOSITION OF A FIRST ORDER FUNCTIONAL DIFFERENTIAL OPERATOR». Известия НАН РК. Серия физико-математическая, вып. 6 (декабрь):90-105. https://journals.nauka-nanrk.kz/physics-mathematics/article/view/1696.