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 "Ellery Queen (house name)"): Several of the main series novels were also ghost-written, but those were controlled and edited by the cousins.
Relevant evidence: No