Setyowisnu, Glagah, Lilik Muzdalifah, & Isnu Aji Saputro.
" ASYMPTOTIC STUDY OF NONLINEAR SPRING OSCILLATION WITH EXTERNAL FORCE USING THE MULTIPLE TIME SCALES METHOD." <em>Jurnal Ilmiah Matematika dan Pendidikan Matematika</em> [Online], 17.2 (2025): 115-132. Web. 17 Jan. 2026