(1)
Mulev, M.; Grupče, L.; Melovski, L.; Derlieva, L. Mineral Matters Content in the Organs of the Species Quercus Frainetto and Quercus Cerris in the Ass. Quercetumfrainetto-Cerris Macedonicum Oberd. 1948, Em. Horvat 1959 in „Galičica,, National Park. MJEE 1994, 2, 37-46.