George Gross was another powerhouse in the pulp/magazine genera. He started off working for his family's studio then branched out and partnered up with the legendary Mort Kunstler with a joint studio in New York. He saw a ton of work with the men's mags of the 60s and also did some great book covers for the Avengers and John Carter novels. Gross died in the early 2000s but left an impressive work of fantastic art in just about every genera. Do some Google-Fu and see some more of Gross' superb art.