4 books in series

The Phantom (Frew Publications)

The Phantom (Frew Publications) is a 2-book series with 4 primary works first released in 1973 with contributions by Lee Falk, Frank S. Shawn, Norman Worker, and Claes Reimerthi.

The Golden Circle
The Swamp Rats
The Phantom #1741: Duel in Venice Part 1 / The Heart of Darkness - Part 1: The Grave of Imhotep
The Phantom #1742: Duel in Venice, Part 2 / Heart of Darkness, Part 2 - The Other Grave