They Knew the Unknown
- Author/Editor: Martin Ebon
- Publisher: New York: The World Publishing Company
- Date: 1971
- Condition: very good
They Knew the Unknown: Fascinating case-studies of famous men and women in history who explored the reality behond our senses. First Edition. Black cloth over blue marbled boards, metalic blue lettering on the spine, original pictorial dust jacket. Ex libris Trevor Hall (ownership signature front fly leaf). 285 pages. Some shelf wear, page edges lightly spotted. Very good condition.