Planet of Dread / Twice Upon a Time

From Author Wars - https://authorwars.com/books/planet-of-dread--twice-upon-a-time-2944698.html

Overview:

Title: Planet of Dread / Twice Upon a Time
Author: Gregory Luce
Year: 2011
Type: Omnibuses

Variant Titles:

2011. Planet of Dread / Twice Upon a Time