I tried too, but since the documentary is simply called "SR-71 Blackbird", it makes it hard. The subtitle "To keep the peace they fly alone... unarmed... into the unknown" ist cool but yields one result: an auction of the movie poster [0]

In turn, the movie poster however let me to a reverence to the movie in the book "SR-71 revealed the inside story" by Richard H. Graham, Col. USAF (Ret).

0: http://auctions.emovieposter.com/Bidding.taf?_function=detai...