Note: A house name owned by Nightstand Books and used by many writers to produce soft porn/sleaze novels in the 1960s. As per http://bookscans.com/Oddities/johndexter.htm, the list of SF authors who are known to have written as "John Dexter" includes Marion Zimmer Bradley, Robert Silverberg, George H. Smith, and Zach Hughes. Other authors of genre interest included Donald E. Westlake, Harry Whittington and Lawrence Block.