Talk:Steffen's polyhedron

Constant volume ?
Can/should we add "[hence] It satisfies the proven bellows conjecture which states that the volume of a flexible polyhedron is invariant under flexing." ? - Rod57 (talk) 10:59, 8 November 2017 (UTC)

When discovered
Can we say when it was discovered/published ? Optimizing the Steffen flexible polyhedron says 1978 but it would be nice to have a better (non-preprint) source. Any source by Steffen himself ? - Rod57 (talk) 11:46, 8 November 2017 (UTC)
 * ... The Above preprint refs "[9] Steffen, K. A symmetric flexible Connelly sphere with only nine vertices. Letter written to Institut des Hautes Études Scientifiques, 1978 (available online at )" [handwritten but not signed or dated?] - Rod57 (talk) 11:57, 8 November 2017 (UTC)

Further reading ? - Optimizing it
Could we add Optimizing the Steffen flexible polyhedron to Further reading ? - Rod57 (talk) 11:37, 8 November 2017 (UTC)