I collect Mercury dimes, among other things, and was wondering if there is any good reference material out there about the known DDOs in this series, such as 1929-S, 1931, 1931-S, 1936, etc. etc. I'd like to know if anyone knows of good reference material on these coins and whether anyone has had any luck cherry picking them since you don't hear much about them compared to other "famous" DDOs. I'd like to go hunting for these!