"Published in an unclassified edition of 'Studies in Intelligence' in 1995, this article is one of the earliest public accounts given of Lima Site 85 and the successful North Vietnamese attack against it on 10 and 11 March 1968. The most definitive account, based on extensive interviews and documentation, appeared five years later in a book by former CIA and Intelligence Community historian Timothy Castle, 'One Day Too Long: Top Secret Site 85 and the Bombing of North Vietnam' (Columbia University Press). This article is part of a forthcoming compendium of Studies articles related to the conflict in Southeast Asia that will be published in support of Defense Department efforts to mark the passage of 50 years since that conflict took place."
Central Intelligence Agency: https://www.cia.gov/
Studies in Intelligence, v.59, no.1 (March 2015)