HRIVNÁK, Richard et al. Distribution and eco-coenotic patterns of the forest orchid Epipactis pontica in Slovakia. In Annals of forest research : journal of forestry and environmental sciences. ISSN 1844-8135, 2014, vol. 57, issue 1, p. 55-69. VEGA 2/0059/11 ; VEGA 1/0362/13 ; VEGA 2/0027/13. CCC, WOS, SCOPUS.