11 books in series
Collector's Library of the Unknown
Collector's Library of the Unknown is a 11-book series with 11 primary works first released in 1882 with contributions by Ignatius L. Donnelly, Sylvan Muldoon, Upton Sinclair, Harry Price, John G. Fuller, Harry Houdini, and J. Allen Hynek.
1882 • 2 Readers • 490 pages
1929 • 1 Reader
1966 • 1 Reader • 350 pages
1929 • 1 Reader • 208 pages
1940 • 1 Reader • 255 pages
1882 • 2 Readers • 490 pages • 5
1972 • 1 Reader • 294 pages • 4
2002 • 1 Reader • 352 pages
1966 • 1 Reader • 465 pages • 4
1972 • 1 Reader • 276 pages
1882 • 1 Reader • 490 pages