Question: Which competitor to "Strange Stories" was edited by John W. Campbell?
Related documents: [0]  [DOC] Strange Stories was a pulp magazine which ran for thirteen issues from 1939 to 1941. It was edited by Mort Weisinger, who was not credited. Contributors included Robert Bloch, Eric Frank Russell, C. L. Moore, August Derleth, and Henry Kuttner. "Strange Stories" was a competitor to the established leader in weird fiction, "Weird Tales". With the launch, also in 1939, of the well-received "Unknown", "Strange Stories" was unable to compete. It ceased publication in 1941 when Weisinger left to edit "Superman" comic books. [END] 
[1]  [DOC] Unknown (also known as Unknown Worlds) was an American pulp fantasy fiction magazine, published from 1939 to 1943 by Street & Smith, and edited by John W. Campbell. "Unknown" was a companion to Street & Smith's science fiction pulp, "Astounding Science Fiction", which was also edited by Campbell at the time; many authors and illustrators contributed to both magazines. The leading fantasy magazine in the 1930s was "Weird Tales", which focused on shock and horror. Campbell wanted to publish a fantasy magazine with more finesse and humor than "Weird Tales", and put his plans into action when Eric Frank Russell sent him the manuscript of his novel "Sinister Barrier", about aliens who own the human race. "Unknown"' s first issue appeared in March 1939; in addition to "Sinister Barrier", it included H. L. Gold's "Trouble With Water", a humorous fantasy about a New Yorker who meets a water gnome. Gold's story was the first of many in "Unknown" to combine commonplace reality with the fantastic. [END] 
Answer: 
"Unknown"
"Unknown"