1. Ausbrooks R. Buswell S. Dalmas S. Devitt S. Diaz A. Hunter R. Smith B. Soiffer N. Sutor R. & Watt S. 2001 Mathematical markup language (MathML) version 2.0. W3C proposed recommendation 8 January 2001 (http://www.w3.org/TR/MathML2/PDFp-MathML-20001113.pdf).
2. Bray T. Hollander D. & Layman A. 1999 Namespaces in XML. W3C recommendation 14 January 1999 (http://www.w3.org/TR/1999/REC-xml-names-19990114).
3. Bray T. Paoli J. Sperberg-McQueen C. M. & Maler E. 2000 Extensible markup language (XML) 1.0 (2nd edn). W3C recommendation 6 October 2000 (http://www.w3.org/TR/2000/ REC-xml-20001006.pdf).
4. Brickley D. & Guha R. V. 2000 Resource Description Framework (RDF) schema specification 1.0. W3C candidate recommendation 27 March 2000 (http://www.w3.org/TR/2000/ CR-rdf-schema-20000327).
5. Bullivant D. Hedley W. J. & Nielsen P. M. F. 2000 The FieldML website (http://www. physiome.org.nz/sites/physiome/fieldml/pages/index.html).