Njakoi aspekti na selištnoto razvitie v gornoto tečenie na reka Strjama prez kăsnata željazna epoha - Kis'ov, Kostadin (Poseliščten život v Drevna Trakija. Studies on settlement life in ancient Thrace. Proceedings of the 3rd International Symposium "Cabyle", 17-21 may 1993, Jambol., 1994)