Twice upon a time
By: by Charles L. Fontenay
Contributors: Tubb, E. C.
Series: Ace double novel books -- D-266
Publisher: Ace Books
Published: 1958
Place of publication: New York
Language: eng
Number of pages: 167
Subjects: Science fiction
Notes: With (inverted): The mechanical monarch/E. C. Tubb. New York : Ace, [c1958].

R. Reginald.  Science fiction and fantasy literature : a checklist 1700-1974, p. 190.