BEYOND EARTH: MAN'S CONTACT WITH UFOS by Ralph Blum with Judy Blum

Some wild and woolly encounters, from Villas-Boas to Pascagoula to Betty and Barney Hill. "The authors predict that by 1975 the government will release definitive proof that extraterrestrials are watching us." 

A sinister looking 1976 reprint.

And a flashy 1978 edition. This title is available to read and download at archive dot org.

Bantam Books, 1974