A 1996 book by PerBrinchHansen? containing 25 of his papers on concurrency dating back to 1967.
http://www.computer.org/cspress/CATALOG/bp07566.htm
I found this quote in the Preface. Sounds like a few people around here, too.
At Regnecentralen I was responsible for the architecture and software of the RC 4000 minicomputer. The RC 4000 real-time control system was my first experience with multiprogramming and semaphores: Article 1: The RC 4000 Real-time Control System at Pulawy (1967). ... The project succeeded because we used the simplest possible techniques to solve an unfamiliar problem of modest size. I have tried to remain true to this ideal throughout my career.