Loess & Bee-eaters VII: Poland; South-East Poland; near Przemysl; near Sandomierz

Sepiol, B., Dudzik, K.,  Mandziak, M.  2012.  Breeding population of the European bee-eater Merops apiaster in the Sandomierz Upland 2001-2012. Naturalia 1, 71-86 (in Polish, English summary)
"all the nests were located in loess banks."