SINGH, B. ON THE OSCILLATION OF AN ELLIPTIC EQUATION OF FOURTH ORDER. Tamkang Journal of Mathematics, [S. l.], v. 27, n. 2, p. 151–159, 1996. DOI: 10.5556/j.tkjm.27.1996.4353. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4353. Acesso em: 5 may. 2024.