SUBIN P. JOSEPH. Exact solutions for Klein-Gordon equation with quadratic non linearity. Malaya Journal of Matematik, India, v. 8, n. 02, p. 642–645, 2020. DOI: 10.26637/MJM0802/0054. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/1473. Acesso em: 16 jul. 2024.