Delbo's work here went unrecognized for a few decades. Here's a panel from his story.
Only the Explorers back-up story is new in issue 15; the Voyage to the Bottom of the Sea story is a reprint.
Explorers in the Unknown—written by Dick Wood—in Voyage to the Bottom of the Sea
|Nov/66||#6||Manhunt in Space||Giolitti Studio|
|Feb/67||#7||The Demons of the Deep Space||Nevio Zeccara|
|May/67||#8||The Hostile Asteroid||Zeccara|
|Aug/67||#9||The Graveyard of Space||Zeccara|
|Nov/67||#10||Mystery of the Magnetized Planet Chapter II||Zeccara|
|Feb/68||#11||Mystery of the Magnetized Planet Chapter III: Uncertain Lift-Off||Zeccara|
|May/68||#12||Prisoners of the "Jelly" Planet||Zeccara|
|Aug/68||#13||Chapter II: Prisoners of the "Jelly" Planet||Zeccara|
|Nov/68||#14||Prisoners of the Jelly Planet—Chapter 3||Zeccara|
|June/69||#15||Runaway Asteroid||José Delbo|