Huynh Trong Duong, and Vo Thi Hoa. “ BUILDING MODELS COMBINING TWO SIMPLE HARMONIC MOTIONS WITH MATHEMATICA SOFWARE”. UED Journal of Social Sciences, Humanities and Education, Vol. 8, no. 3A, Aug. 2018, pp. 17-21, doi:10.47393/jshe.v8i3A.693.