Question: Showboat World, written in 1975, is the second, stand-alone novel in a pair of science fiction novels by Jack Vance, was an American mystery, fantasy, and science fiction writer, he also wrote how many mystery novels, under the pseudonym Ellery Queen?
Sentence (from "Jack Vance"): John Holbrook "Jack" Vance (August 28, 1916 – May 26, 2013) was an American mystery, fantasy, and science fiction writer.
Relevant evidence: No