Leonard Stringfield
Leonard Stringfield was the pioneer of American UFOlogy who brought the subject
of UFO retrievals (a term he 'invented') into the mainstream of UFOology. Retrievals
stories up to then had been the realm of 'crackpots' and associated with the dubious
claims of the 1950s Contactees.
He devoted much of his time to investigating these retrieval cases.
Books:
The Ufo Crash-Retrieval Syndrome: Status Report Ii: New Sources (1980)
The Ufo Crash/Retrievals: Amassing The Evidence - Status Report Iii (1982)