The Door Through Space / Rendezvous on a Lost World

From Author Wars - https://authorwars.com/publications/the-door-through-space--rendezvous-on-a-lost-world-38610.html

Overview:

Title: The Door Through Space / Rendezvous on a Lost World
Author: Marion Zimmer Bradley, A. Bertram Chandler
Year: 1961
Publisher: Ace Books
Price: $0.40
Pages: 132+124
Binding: dos
Type: Omnibus
Title Reference: Rendezvous on a Lost World
Notes:
- Cover for Rendezvous on a Lost World has "First Book Publication"
  - Artist is not credited, EMSH is on the artwork; 124 pages
- Cover for The Door Through Space has "Complete Novel"
  - The artist is not credited, EMSH is on the artwork; 132 pages