Sartabanov Zhaishylyk Almaganbetovich, Omarova Bibigul Zharbolovna, и Kerimbekov Akylbek. 2019. «RESEARCH OF MULTIPERIODIC SOLUTIONS OF PERTURBED LINEAR AUTONOMOUS SYSTEMS WITH DIFFERENTIATION OPERATOR ON THE VECTOR FIELD». Известия НАН РК. Серия физико-математическая, вып. 1 (февраль):5-13. https://journals.nauka-nanrk.kz/physics-mathematics/article/view/1155.