Although generally called a science fiction writer he also wrote Westerns using the names Kelly P. Gast, J. B. Masterson, and Jack Logan. As he could also speak six languages he did translating work as well. His science fiction career began during 1955 with a story in the magazine Astounding. He later produced several novels which gained some note for their interest in time travel and Latin America. Several writers, including Gardner Dozois, tend to consider him as a neglected author.