HORRORS UNKNOWN. New York: Walker and Company, . Octavo, boards. First edition. Collects "The Challenge from Beyond," a collaborative story by C. L. Moore, A. Merritt, H. P. Lovecraft, Robert E. Howard and Frank Belknap Long, and ten other stories by Edison Marshall, Frank Norris, C. L. Moore, Fitz-James O'Brien, Seabury Quinn, Francis Stevens, Ray Bradbury, Ray Bradbury and Henry Hasse, Edwin L. Sabin and W. Fenimore. Bleiler, The Guide to Supernatural Fiction 1201. Carter, The Vampire in Literature (1989), p. 89. Reginald 10450. A fine copy in fine dust jacket with just a hint of the usual tanning. (#156041).
"First published in the United States of America in 1971 ..." on copyright page.