It's in Swami, Issue 13 (January 1973), or on page 51 of Richard's book. Also excellent along these lines is Bill Goldman's "Like a Bird on a Wire" in his Magic Bar & Grill issue 7 and Docc Hilford's "Brother of All Book Tests" (which I believe he now calls something else).
Docc Hilford's version is called "The Wizard's Manual," and is available commercially. I was thinking just yesterday about the similarities between this trick and "Whim of Tituba" in Anneman's Practical Mental Effects, although the latter is a bizarre trick focusing on communion with the afterlife.
Art sold these himself in the 1970's....it is easy to make up yourself....just use a clean razor to make nice "short" pages in popular paperbacks. I occasionally still use the effect in a show....plays fine.