DR. ALOK KUMAR,. SPECTRAL THEORY OF EIGENFUNCTION EXPANSION WITH SECOND ORDER DIFFERENTIAL EQUATION. Journal of Validation Technology, ISSN: 1079-6630, E-I SSN: 2150-7090 UGC CARE II, [S. l.], v. 30, n. 1, p. 66–74, 2024. DOI: 10.1080/jvtnetwork.v30i1.59. Disponível em: https://jvtnetwork.com/index.php/journals/article/view/59. Acesso em: 23 dec. 2024.