4 books in series
Operation Otherworld
Operation Otherworld is a 4-book series with 4 primary works first released in 1953 with contributions by Poul Anderson.
#1
1971 • 7 Readers • 211 pages • 4
#2
1999 • 2 Readers • 438 pages
#2.5
1953 • 37 Readers • 232 pages • 3.5
#3
1974 • 10 Readers • 207 pages • 4