Study sites in Vitosha Mts., SW Bulgaria as follows: site 1 – 42°36'13.2"N, 23°15'04.0"E, site 2 – 42°36'20.5"N, 23°17'39.4"E, site 3 – 42°34'05.1"N, 23°17'52.6"E Study sites 1 and 2 were in open woodlands in the coniferous forest belt. Study site 3 was in the subalpine meadows just above the coniferous forest belt.

  Part of: Kozuharova E, Simeonov V (2022) Monitoring bumblebee pollinator visits to the medicinal plant Gentiana asclepiadea L. (Gentianacese) – a comparison between the periods 1990–1994 and 2017–2020. In: Chankova S, Peneva V, Metcheva R, Beltcheva M, Vassilev K, Radeva G, Danova K (Eds) Current trends of ecology. BioRisk 17: 317-327.