@article {2428,
	title = {Socially parasitic ants of Greece.},
	journal = {Biologia Gallo-Hellenica},
	volume = {20},
	year = {1993},
	pages = {183{\textendash}189},
	author = {Buschinger A. and Douwes P.}
}
@inbook {2385,
	title = {Review of the hymenopteran fauna (Insecta: Hymenoptera) of the Vratchanska Planina Mountains with a checklist of species},
	booktitle = {Faunistic diversity of Vrachanski Balkan Nature Park. Part 2, EDds.: Bechev, D., Georgiev, D.},
	year = {2019},
	pages = {81-106},
	publisher = {ZooNotes, Supplement 7, Plovdiv University Press},
	organization = {ZooNotes, Supplement 7, Plovdiv University Press},
	address = {Plovdiv},
	author = {Toshko Ljubomirov}
}
