theory in a nutshell,
by A. Zee (Princeton U. Press, March 10, 2003),
"A Binary Code for the World," pp. 410 ff.
Coding fermions and Projective structures,
by Carol von der Lin.
Website, undated-- but see her Usenet posting
5-bit coding of the fermions, Nov. 24, 2003
On Spekkens' toy system and finite geometry,
comment by Steven H. Cullinane
at The n-category Cafe, Sept. 2, 2007
A fully epistemic model for a local hidden variable emulation of quantum dynamics, by Michael Skotiniotis, Aidan Roy, and Barry C. Sanders, June 30, 2007. arXiv:0707.0074.