Sartabanov, Zh.A., B.Zh. Omarova, и A. Kerimbekov. 2020. «RESEARCH OF MULTIPERIODIC SOLUTIONS OF PERTURBED LINEAR AUTONOMOUS SYSTEMS WITH DIFFERENTIATION OPERATOR ON THE VECTOR FIELD». Physico-Mathematical Series, вып. 1 (февраль):5-13. http://550300.0ncwlf7ax.asia/physics-mathematics/article/view/386.