The Flintstones at the New York World's Fair (1964/65))

Comics Core | Suggest Keys
1

Core incorrectly considers this a key, and calls this the first appearence of Sandman (Wesley Dodds). That should be New York World’s Fair Comics #1 (1939).

2

Something must be wrong in your database, in Core it is correct. Can you try be deleting it and adding it back?