| 1 | [1]Universal design : solutions for a barrier-free living, Oliver Herwig, Birkhäuser, Basel, Boston, 2008 |
| 2 | [2]Smart technology for aging, disability, and independence: the state of the science, William C. Mann (ed.), Wiley-Interscience, Hoboken, New Jersey, 2005 |
| 3 | [3]Universal design: best practice, Peter Zec (ed.), Red Dot Edition, Essen, 2009 |
| 4 | [4]Universal principles of design, William Lidwell, Rockport, Gloucester, Mass., 2003 |