DR. P. G. KHOT, and SANJAY SRIVAS. “INTRODUCTION OF SPATIAL DATABASE SPATIAL DATA TYPES, SPATIAL INDEXING, GEOGRAPHIC INFORMATION SYSTEMS (GIS) &Amp; QUERY STRUCTURE”. JournalNX - A Multidisciplinary Peer Reviewed Journal, Feb. 2021, pp. 137-42, https://repo.journalnx.com/index.php/nx/article/view/2048.