Azeez, Ali Abid Hussan, and Rehab Flaih Hassan. 2019. “Using Space-Filling Curves to Improve the Quad Tree for Spatial Indexing”. Journal of Al-Qadisiyah for Computer Science and Mathematics 11 (3):Comp Page 94-104. https://doi.org/10.29304/jqcm.2019.11.3.610.