LAITH K. SHAAKIR; SAAD S. MARAI. quasi-normal Operator of order n. Tikrit Journal of Pure Science, [S. l.], v. 20, n. 4, p. 167–169, 2023. DOI: 10.25130/tjps.v20i4.1231. Disponível em: https://tjpsj.org/index.php/tjps/article/view/1231. Acesso em: 17 jun. 2025.