I got my copy of Michael Plass' dissertation today. A cursory overview shows that this document will provide some insight on using Knuth element model for page breaking but it also makes clear that we still have to come up with solutions for certain tricky problems that he didn't have to deal with back then. At any rate, the dissertation seems more helpful than the two documents we found by Brüggemann-Klein, Klein and Wohlfeil.
Jeremias Maerki
