Hey there!

What kind of book are you seeking to write? The literature on those three agencies you mentioned is vast, and the lines between academic and journalistic works are sometimes blurry. Is there any specific aspect that you are interested in?

Most of the works that are published about these agencies are either focussed on one specific Cold War crisis or espionage affair, or they tend to cover the entire period of the Cold War. Not many works specifically focus on the time-frame you have asked for.

For instance, if your book is set in Berlin, my immediate recommendation would be David Murphy's Battleground Berlin: CIA vs KGB in the Cold War, which emerged in 1997 and although largely written by journalists and intelligence officers who actually worked in Berlin, it is still one of the most relevant studies on Cold War operations in Berlin before the construction of the Wall in 1961 due to the revelations of primary sources in that book.

If you really want to get into the wilderness of mirrors, the counterintelligence war, then perhaps former CIA officer's Tennent H. Bagley's Spy Wars: Moles, Mysteries and Deadly Games is of use to you. It is not an academic work, but a mixture of memoir, journalism and history, by a Cold War veteran who goes back into the past, in which he participated, to revisit some of the Cold War's most notorious moles and unsolved mysteries. It focusses mainly on episodes during the 1960's, such as the Penkovsky, Popov, and Nosenko cases.

May I also slip in some fictional recommendations here. I know you have come for history sources, but sometimes, fiction can also shed light on the truth. John Le Carre, who briefly worked for the British counterintelligence MI5 and was also shortly stationed in Germany for MI6 during the early Cold War, has fictionalised his experiences in fantastic novels such as The Spy Who Came in from the Cold (1963), Tinker Taylor Soldier Spy (1974) and many more. Historians take the study of spy fiction serious for a few reasons. Firstly, real people often try to imitate fiction. I can't imagine how many new recruits MI6 and MI5 had to liberate from their indoctrination by public ideas of espionage based on James Bond and Le Carre novels. Fiction can affect the real world, and in case of Le Carre, his fiction shows us how the author has at least experienced the Cold War spy world. Even though he uses fictional agencies, creates fictional plots, he can also provide you with a lot of small details of what it could be like in 1960's and 70's espionage. The bureaucratic turf wars, the culture of secrecy, the tradecraft, and even the banality of the whole affair. Le Carre's works reflect a certain disappointment with espionage, expressed in themes such as betrayal, inspired by the British spy cases of George Blake and Kim Philby that occurred during his time in intelligence.

Kristie Macrakis has produced the best scholarly works on the East German Stasi in recent years. Seduced by Secrets: Inside the Stasi's Spy-Tech world (2008), is one of the best scholarly works available on the Stasi, but it does focus on scientific-technological espionage. That being said, such a focus is justified given that the bulk of the resources of both the Stasi and KGB went to scientific-technological spying. If you'd like a more general overview of what the Stasi was, then I can recommend Gary Bruce's The Firm: The Inside Story of the Stasi.

A concise, recent history of KGB foreign intelligence is offered by Jonathan Haslam, Near and Distant Neighbours: A New History of Soviet Intelligence, offering both a collection of specific spy cases, as well as a history of the Soviet Union viewed through the lens of the ever-declining fortunes and morale of the KGB and GRU. For a more detailed exposé of KGB operations in the West, the go-to work still remains the 1999 publication by Christopher Andrew in cooperation with Vasili Mitrokhin, The Sword and the Shield: The Mitrokhin Archive and the Secret History of the KGB.

Paul Maddrell's Spying on Science: Western Intelligence in Divided Germany 1945-1961 may also fit in well if your story takes place against the background of espionage in Germany. His contribution is important for highlighting the extent of cooperation among the Western intelligence services.

Michael Warner, a historian who has worked as the CIA's official historian as well, has written an interesting work looking at the entire Cold War era and beyond in The Rise and Fall of Intelligence: an International Security History. Here you will find perhaps some more inspiration on specific aspects of Cold War espionage.

As I said, there is a lot that has been published about these agencies, and one might say they each constitute their own sub-field within the larger historiography of the Cold War and intelligence studies. The history of the KGB for instance can be subdivided into numerous fields such as KGB Cold War foreign operations, KGB domestic repression, Stalin-era espionage, Stalin-era secret police, the Great Terror, the Gulags etc. In similar fashion, the CIA's history is so rich and diverse that scholars have specialized in specific aspects of the CIA: its relationship with Washington, CIA Cold War operations against the Soviets, CIA failures, CIA operations in the Middle East, East Asia, South America etc, Covert Operations, CIA analysis, CIA relations with the FBI, the War on Drugs, War on Terror, to highly specific cases.

If there is anything specific you'd like to know more about, I'm sure we can help looking for it.