Alsid, Safa Ahmed Babikir. “Harmonic C^*-Categories of Longitudinal Pseudo Differential Operators over Flag Variety”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 59, no. 1, June 2021, pp. 100-11, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/12717.