@article {Swinburne1992,
	title = {The stratigraphy of the Campanian-Maastrichtian rudist beds of Bulgaria and a reassessment of the range of the genus Pironaea},
	journal = {Cretaceous Research},
	volume = {13},
	year = {1992},
	pages = {191{\textendash}205},
	keywords = {RCBS, TIP},
	doi = {10.1016/0195-6671(92)90035-O},
	url = {http://www.sciencedirect.com/science/article/pii/019566719290035O},
	author = {Swinburne, N H M and Bilotte, M and Pamoukthiev, A}
}
