THE GATE OF TIME 1966 Belmont 1st Printing	THE GATE OF TIME 1970 Belmont Reprint	THE GATE OF TIME 1974 Quartet 1st British Printing	THE GATE OF TIME expanded and retitled TWO HAWKS FROM EARTH 1979 Ace Reprint
THE GATE OF TIME expanded and retitled TWO HAWKS FROM EARTH 1985 Berkley Reprint