The following documents of the International Organization for Standardization (ISO) relate to SQL:
ISO/IEC 9075-1:2008, Information technology—Database languages—SQL—Part 1: Framework (SQL/Framework)
ISO/IEC 9075-2:2008, Information technology—Database languages—SQL—Part 2: Foundation (SQL/Foundation)
ISO/IEC 9075-3:2008, Information technology—Database languages—SQL—Part 3: Call-Level Interface (SQL/CLI)
ISO/IEC 9075-4:2008, Information technology—Database languages—SQL—Part 4: Persistent Stored Modules (SQL/PSM)
ISO/IEC 9075-9:2008, Information technology—Database languages—SQL—Part 9: Management of External Data (SQL/MED)
ISO/IEC 9075-10:2008, Information technology—Database languages—SQL—Part 10: Object Language Bindings (SQL/OLB)
ISO/IEC 9075-11:2008, Information technology—Database languages—SQL—Part 11: Information and Definition Schemas (SQL/Schemata)
ISO/IEC 9075-13:2008, Information technology—Database languages—SQL—Part 13: SQL Routines and Types using the Java Programming Language (SQL/JRT)
ISO/IEC 9075-14:2008, Information technology—Database languages—SQL—Part 14: XML-Related Specifications (SQL/XML)
You can obtain a copy of ISO standards from this address:
or from their Web store:
http://www.iso.org/iso/store.htm