Hopalong Cassidy - An American Legend
Hopalong Cassidy by Clarence E. Mulford
Hopalong Cassidy Collectibles by Joseph J. Caro
Bar-20 (A Hopalong Cassidy Novel) by Clarence E. Mulford
Bar-20 : The Life of Clarence E. Mulford, Creator of Hopalong Cassidy, With Seven Original Stories Reprinted by Francis M. Nevins