| 3 | www.mos.org/sin/Leonardo | Exploring 'Leonardo' |
| www.asap.unimelb.edu.au/hstm/ htsm_ove.htm |
Visual library for the history of Science, Technology and Medicine | |
| www.bbc.co.uk/education/wheel/hitech.htm | History of Technical advances. | |
| www.learningcurve.pro.gov.uk | Public Records Office |