A.SH.SHALDANBAYEV; M.I.AKYLBAYEV; A.A.SHALDANBAYEVA; A.ZH.BEISEBAYEVA. ON THE SPECTRAL PROPERTIES OF A WAVE OPERATOR PERTURBED BY A LOWER-ORDER TERM. Известия НАН РК. Серия физико-математическая, [S. l.], n. 4, p. 22–29, 2019. Disponível em: https://journals.nauka-nanrk.kz/physics-mathematics/article/view/1672. Acesso em: 23 ноя. 2024.