M., Salim Dawood, and Jaafer Hmood Eidi. “On (P*-N) Quasi Normal Operators Of Order ‘n’ In Hilbert Space”. Al-Mustansiriyah Journal of Science, vol. 32, no. 1, Feb. 2021, pp. 10-13, https://doi.org/10.23851/mjs.v32i1.920.