In my opinion one of the most difficult puzzles. Unfortunately I was requested by Minoru Abe to remove screen shots and the shortest solutions from my website. If you want to see and play them visit Nick Baxter's site. If I may be little immodest: I have found the shortest 96-move solution for Slide-31 level which (very likely) wasn't known previously.
If you have any question or request regarding these levels please contact me.