Unicode® Standard Annex #31| www.unicode.org
Updates and Errata| www.unicode.org
About Versions of the Unicode® Standard| www.unicode.org
Unicode® Standard Annex #41| www.unicode.org
Unicode® Standard Annex #29| www.unicode.org
Unicode® 15.1.0| www.unicode.org
Unicode Character Encoding Stability Policies| www.unicode.org