Reference

Jindrich jun. Chrtek, Karol Marhold (1998): Taxonomy of the Hieracium fritzei Group (Asteraceae) in the Sudeten Mts. And the Wast Carpathians. (Studies in Hieracium sect. Alpina II.). – Phyton, Annales Rei Botanicae, Horn – 37_2: 181 - 217.