I think the James Bond strip was signed by Ian Fleming and even though the stories were adapted by others, they were based on Fleming's novels. The logo for the Tarzan strip always said "Tarzan by Edgar Rice Burroughs" but I don't know if he provided the continuity or if the strip was ghosted. Again, many of the Tarzan strips were based on actual books written by Burroughs and I think the captions often came from Burrough's books.