1. AudioMath for European Portuguese,
http://lpf-esi.fe.up.pt/~audiomath
2. W3C – World Wide Web Consortium,
http://www.w3c.org
3. MathML – Mathematical Mark-up Language,
http://www.w3.org/Math
4. Pierce, J.: An Introduction to Information Theory. Symbols, Signals and Noise. Dover Publications Inc, New York (1961)
5. Monaghan, A., Fitzpatrick, D.: Browsing Technical Documents: Document Modelling And User Interface Design. In: BULAG 1999 (1999)