The Adventures of Jo, Zette and Jocko

The Adventures of Jo, Zette and Jocko is a comic book series created by Belgian artist/writer Hergé. The protagonists of the series are two young children, brother and sister Jo and Zette Legrand and their pet monkey Jocko. Jo, Zette and Jocko have appeared on the rear covers of some The Adventures of Tintin editions, but never appear in the stories.

All 5 albums were written in French  between 1935 to 1958, but translated in English much later.

The Secret Ray - 2 vol set 

Volume 1: The 'Manitoba' No Reply -- (No 1)

Volume 2: The Eruption of Karamako -- (No 2)

First English print: 1994

Mr. Pump's Legacy -- (No 3)

First English print: 2003

Destination New York -- (No 4)

First English print: 2003

The Valley of the Cobras -- (No 5)

First English print: 2003