Links to references found on the web:

The Terence Higgins Trust, http://www.atp.org.uk

Avert, an International AIDS Education and Medical Research Charity, http://www.avert.org

http://www.thebody.com/sfaf/sfafpage.html

Other useful links:

To view some of the molecules the Chime plugin is required and can be downloaded from http://www.mdlchime.com/chime/

The Protein Data Bank, to find 3-D biological macromolecular structure data, http://rcsb.org/pdb/

For easier searching of the Protein Data Bank (PDB) try, http://pdblite.org/