https://www.goodreads.com/book/show/...om_search=true
Special Forces Berlin: Clandestine Cold War Operations of the U.S. Army's Elite, 1956-1990
by James Stejskal
I heard about this on the Spycast podcast, here:
https://audioboom.com/posts/6137930-...james-stejskal
It's next up on my to-read pile. These were supposed to be the stay-behind SF, when/if the Sovs crossed the borders. According to the interview, the Sovs and East Germans never knew they were there. There were some covert ops outside the city, too.