Mirage for Planet X / Police Your Planet

From Author Wars - https://authorwars.com/publications/mirage-for-planet-x--police-your-planet-453320.html

Overview:

Title: Mirage for Planet X / Police Your Planet
Author: Stanley Mullen, Lester del Rey
Year: 2014
ISBN-10: 9781612872094
Publisher: Armchair Fiction
Price: $12.95
Pages: 216
Binding: Trade Paperback
Type: Omnibus
Title Reference: Mirage for Planet X
Notes: Data from publisher's Web site. Data from Armchair Fiction as of 06/16/14. The art for Mirage for Planet X is the same art as for the Fantastic Universe, September 1955 issue, where Mel Hunter is credited. The art for Police Your Planet is the same as for the 1956 Avalon Books hardcover edition where Ed Emshwiller is credited.