Abuelyamen, S. H. “THE HIJIRI CALENDAR AND ITS CONFORMANCE WITH THE GREGORAIN CALENDAR BY MATHEMATICAL CALCULATIONS: 31st May 2022; 07th February 2023; 16th February 2023; 17th February 2023”. MATTER: International Journal of Science and Technology, vol. 9, Mar. 2023, pp. 01-19, doi:10.20319/mijst.2023.9.0119.