Thrift Shop Book Covers: "The Warsaw Document"

The Warsaw Document, by Adam Hall, was published as a hardcover by William Heineman Ltd in 1971, but the edition that caught my eye was the paperback edition published by Fontana in 1978. The cover is cold war perfect with a Mercedes—the choice of every good spy—running a barricade. The artist: Tony Roberts

The first paragraph:

There would be no warning, I knew that.

The Warsaw Document, is the fourth (of 19) novels featuring British spy Quiller. The Quiller books were published as by Adam Hall, which was a pseudonym for Elleston Trevor.