London publisher from 1967
Library of Congress identifies "Sphere Books Limited", earliest found 1967.
Wikipedia "Sphere Books" begins, "Sphere Books is the name of two British paperback publishers." --the entire lead section (April 2022)
Wikipedia coverage crucially includes "Little, Brown Book Group", which implies the sequence:
* Sphere, or Sphere Books; 1967 to 1992
* Warner, Warner Books (UK)
; 1992 to 2006
, or revival of Sphere Books, 2006 to present
Do not merge this with Sphere!!