Appendix A: References
- CSS1
 - "Cascading Style Sheets, level 1," B. Bos, H. Wium Lie, eds., W3C Recommendation 17 Dec 1996, revised 11 Jan 1999. Available at http://www.w3.org/TR/REC-CSS1/.
 - CSS2
 - "Cascading Style Sheets, level 2," B. Bos, H. Wium Lie, C. Lilley, and I. Jacobs, eds., W3C Recommendation 12 May 1998. Available at http://www.w3.org/TR/CSS2/.
 - CSS21
 - "Cascading Style Sheets, level 2 revision 1,"  B. Bos, T. Çelik,  I. Hickson,   H. Wium Lie, eds., W3C Candidate Recommendation 25 February 2004.  Available at:  http://www.w3.org/TR/CSS21/
            
 - CSS3
 - 
               [CSS 2.1 and CSS 3] Roadmap, CSS WG's table of modules and publication dates.
 - HTML4
 - "HTML 4.01 Specification," D. Raggett, A. Le Hors, I. Jacobs, eds.,  W3C Recommendation 24 December 1999. Available at http://www.w3.org/TR/html401/
            
 - WCAG20
 - "Web Content Accessibility Guidelines 2.0,"  B. Caldwell, M Cooper, L Guarino Reid, and G. Vanderheiden, eds., W3 Recommendation 12 December 2008, http://www.w3.org/TR/2008/REC-WCAG20-20081211.  The latest version of WCAG 2.0 is available at http://www.w3.org/TR/WCAG20/.
              
 - XHTML1
 - "XHTML 1.0 The Extensible HyperText Markup Language (Second Edition)," S. Pemberton, et al.,  W3C Recommendation 26 January 2000, revised 1 August 2002. Available at:  http://www.w3.org/TR/xhtml1/.