His Ghosts and more ghosts, 1963.

Biog. and genealogy master index, 2nd ed: (Arthur, Robert, 1909-1969)

Biog. resource center (St. James guide to horror, ghost & gothic writers), Nov. 5, 2009 (Robert (Andrew) Arthur; b. Nov. 10, 1909, Corregidor Island, Philippines; d. May 1, 1969; American; pseudonyms: Andrew Fell, Anthony Morton, Jay Norman, John West, Mark Williams; freelance writer)

Wikipedia, June 27, 2016 (Robert Arthur Jr. ; Robert Jay Arthur Jr. (November 10, 1909 in Fort Mills, Corregidor Island-May 2, 1969 in Philadelphia) was a speculative fiction writer known for his work on The Mysterious Traveler radio series and his series of young adult novels, The Three Investigators. He also wrote scripts for television.)