La porte des ténèbres

From Author Wars - https://authorwars.com/publications/la-porte-des-tenebres-419571.html

Overview:

Title: La porte des ténèbres
Author: Alan Haigh
Year: 1977
ISBN-10: 2702406165
Publisher: Librairie des Champs-Élysées
Pages: 222
Binding: Paperback
Type: Novel
Title Reference: La porte des ténèbres
Notes: Probable first printing. No AI; DL = 3rd trimester 1977. No price on book. Artist not credited, cover also used here (with speculations about artist).