General: External References
- [HTML401]
https://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.2.2. - [ISO639]
https://www.infoterm.info/standardization/iso_639_1_2002.php,https://www.loc.gov/standards/iso639-2/(contains also ISO 639-1 language codes). - [ISO3166]
https://www.iso.org/iso/home/standards/country_codes.htm. - [ISO8601]
https://www.iso.org/iso/catalogue_detail?csnumber=40874,https://en.wikipedia.org/wiki/ISO_8601. - [RFC1945]
https://tools.ietf.org/html/rfc1945. - [RFC2104]
https://tools.ietf.org/html/rfc2104. - [RFC4648]
https://tools.ietf.org/html/rfc4648. - [RFC5545]
https://tools.ietf.org/html/rfc5545.