6 books in series

The Black Widowers

The Black Widowers is a 6-book series with 6 primary works first released in 1974 with contributions by Isaac Asimov.

I racconti dei Vedovi Neri
More Tales of the Black Widowers
Casebook of the Black Widowers
Banquets of the Black Widowers
Puzzles of the Black Widowers
Gli enigmi dei Vedovi Neri
The Return of the Black Widowers