De Courcy, Ken & Jack Yates: Jack Yates' Card Caprice ©1979 The Supreme Magic Co., Bideford, England Softcover, saddle-stitched, 8x10", 11 pages

Image from Magicref

Comments: Edited, illustrated with additional notes by Ken De Courcy

Contents (from book, updated Apr 2020)

2 Introduction
3 Jack's Wallet: A duplicate of a freely chosen card is found in an un-gimmicked Wallet
6 Jack's Line Up: impromptu card revelation effect with audience participation
8 Additional Ideas (Ken de Courcy): tips for modifications, alternate approaches, presentation for the above effect