abd workouts

Sorry guys I know this is beating a dead horse but...
Afew years ago a buddy gave me a poor copy of an ab w/o that consited
of 10 or 15 "levels" of difficulty. It Mainly consisted of hanging
crunches and progressed to hanging straight leg raises coupled with leg
lifts and various lying crunches. These were very effective for me. I
have lost the copy in a move. Anyone know of this system? I think it
may have been a stanford based study. Thanks for any help tracking
these down.
Keith