The World Swappers - John Brunner - Ace Books - 1959 - 153 pp. Science Fantasy - No 21 - 1957 - 128 pp - (John Brunner / E C Tubb / Brian W Aldiss / Lan Wright etc.). Authentic Science Fiction Monthly - No 49 - 1954 - 1955 - 141 pp - (E C Tubb / Dan Morgan / J Burke etc.).
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