qgis - Calculate minimum distance between feature types in PostGIS? - Geographic Information Systems Stack Exchange
20. Geometry Constructing Functions — Introduction to PostGIS
postgis - Use ST_DWithin on WGS84 geometry data - Geographic Information Systems Stack Exchange
WKTRasterTutorial01 – PostGIS
sql - How can I return all the rows in a PostgreSQL/PostGIS table within a radius of Xkm provided by a longitude and latitude value? - Stack Overflow
postgis - Using ST_Transform() to get the length of a LineString using SRID 4326 returning very small numbers - Geographic Information Systems Stack Exchange
Part 1: Getting Started With PostGIS: An almost Idiot's Guide