I struggle to find any, I think about diary, as written by someone who was at the heart of the war, with some proper understanding of the things happening around him, like the "Berlin Diary" from William Shirer.
I really enjoyed Shirer's "Berlin Diary", an American foreign correspondent's experience in the first years of WW2, and his growing disillusionment through time, and I was hoping to find something similar for the Yugoslav wars; I'd like a book that looks at the situation on a wider scale, and also is factual - which might be a bit naive to search for in a highly intense war time.
I found Sarajevo: A War Journal by Zlatko Dizdarevic, Zlata's Diary by Zlata Filipović. Even General Mladic kept a journal. My concern is that I don't think Zlata's Diary would look at the things at a wider scale, and Mladic's journal would say more about himself, than about the war, as I think it is highly biased because of him being a "warlord". I will certainly pick up Zlatko Dizdarevic's book, but I was searching for a more factual book - which might be a bit naive to search for in a highly intense war time.