The book remains a significant source for historians because Boljkovac was a direct participant in high-stakes negotiations and security decisions during the 1990s. His perspectives often conflicted with the "official" narrative of the time, leading to significant public debate upon its release.
Marko looked at the "Save" icon. He realized that possessing the PDF was one thing, but sharing the truth contained within it was another battle entirely. He looked out the window at the Korana river, realizing that just like the water, history flows in ways we cannot always control—but we can at least try to document its course.
If the book isn't available, maybe switch to a different approach. Perhaps discuss the author's other works if available, or compare to similar texts. Also, include references in the academic paper format, but note the source limitations since the book might be obscure.