Colour ringing programme of the lesser spotted eagle (Aquila pomarina) population in Slovakia and its new results in the period 2009–2012
Dravecký, Miroslav, Danko, Štefan, Hrtan, Ervín, Kicko, Ján, Maderič, Boris, Mihók, Jozef, Balla, Miloš, Belka, Tomáš, Karaska, Dušan
The nesting of the Eurasian eagle-owl (Bubo bubo) in a man-made building
Hrtan, Ervín
The first observation of the Levant sparrowhawk Accipiter brevipes (Severtzov, 1850) in Slovakia
Danko, Štefan, Hrtan, Ervín