'A' format 439pp plus NEL Bestsellers listing.
Reprinted March 1980, December 1981, July 1982, November 1982
NB: last line of publishing credits still lists ISBN 0450031063 (the Feb '77 edition)
I've still entered pub date as 1977, as subsequent dates listed are reprints. The ISBN is from rear cover, whereas the title-page verso lists the 1977 one (which it seems has also been entered for the 1988 edition) This copy was purchased in early 1983 for the cover price of £1.95 . Bargain!