Karakiev, T. and Tzonev, R. 2015. Saxifrago ferdinandi-coburgi-Seslerietum actarovii – a new association from the subalpine belt of the Slavianka (Orvilos) Mts. (Bulgaria ). Hacquetia. 10, 1 (Aug. 2015). DOI:https://doi.org/10.2478/v10028-011-0004-8 .