1. PMTM4, a processing model for XML Topic Maps,
http://www.topicmaps.net/pmtm4.htm
, S. Newcomb and M. Biezunski (eds).
2. ISO/IEC 13250 topic maps,
http://www.y12.doe.gov/sgml/sc34/document/0129.pdf
, 1999, (since decembre 2001, the DTD of XTM 1.0 is included within the ISO 13250 specification).
3. Resource Description Framework (RDF) model and syntax specification,
http://www.w3.org/TR/REC-rdf-syntax/
, 1999, O. Lassila and R.R. Swick (eds).
4. Topic map foundational model requirements,
http://www.y12.doe.gov/sgml/sc34/document/0266.htm
, 2001, G. Moore and L.M. Garshol (eds).
5. XML Topic Maps (XTM) 1.0,
http://www.topicmaps.org/xtm/1.0/
, 2001, S. Pepper and G. Moore (eds).