http://www.cit.gu.edu.au/~anthony/kites/tetra/bell/

http://www.grunch.net/synergetics/bell.html

http://www.grunch.net/synergetics/ivm.html

http://www.4dsolutions.net/ocn/urner.html

LAS COMETAS TETRAÉDRICAS DE ALEXANDER GRAHAM BELL

http://usuarios.lycos.es/jmsuay/cometas/bell.htm

and the Octet Truss
http://www.grunch.net/synergetics/bell.html

Bell Tetrahedral Kite
http://www.cit.gu.edu.au/~anthony/kites/tetra/bell/

Synergetic Crystallography 101
http://www.4dsolutions.net/ocn/xtals101.html

tetrahedron, and you get a cube
http://www.activeworlds.com/edu/events/transcript092799.pdf