Ken's Memory System: 24 Hour Course By Mason, Ken Books / Paperback Art & Performing Arts › Theater Publisher: McCowat-Mercer Press, January 1944 Price $25.04 Free Shipping Send to a friend Used - Good Good condition. Book slightly curled. (magic, memory) $25.04 1 in Stock at Warehouse Quantity Add Free Shipping to continental U.S. OR $1.00 per item discount if shipped to store.