Konstantinov & Brostilova 1997 Konstantinov, Konstantin; Brostilova, Maria (1997). "The area of Quercus hartwissiana (Fagaceae) and opportunities of its extension in Bulgaria. In: Bocconea. Band 5". Bocconea: Monographiae Herbarii Mediterranei Panoramitani Sub Auspiciis Societatis Botanicorum Mediterraneorum "Optima" Nuncupate Editae. ISSN1120-4060.