Magazine format. The author (April 23, 1923 – May 8, 1993) was an American writer of fantasy fiction, science fiction, and crime fiction, as well as the author of many stories that do not fit into a genre niche. 'The Riddle of Jack the Ripper' is an 11pp. factual work taken from 'Cavalier Magazine Vol. 10, No.82', and has a front page illustration by Sandy Kossin (a cartoonist and illustrator who created numerous magazine illustrations, paperback covers and film posters throughout his career). He was one of the most in-demand vintage paperback cover artists during the 1960s and '70s. The article preceding this one was entitled 'The Ace Who Spawned Richthofen' by William E. Barrett, featuring Oswald Boelcke. The Ripper content does not appear on the cover, which perhaps explains why it has been overlooked. Seven loose, sunned and fairly fragile pages which have sl. chipped edges. Vg. Extremely scarce.