@article {Smith1999,
	title = {Late Cretaceous{\textendash}early Tertiary echinoids from northern Spain, implications for the Cretaceous-Tertiary boundary},
	journal = {Bulletin of the Natural History Museum (Geology Series)},
	volume = {55},
	number = {2},
	year = {1999},
	pages = {81{\textendash}137},
	keywords = {RCBS, TIP},
	url = {http://www.nhm.ac.uk/resources-rx/files/spainpart1-84721.pdf},
	author = {Smith, Andrew B and Gallem{\'\i}, J and Jeffery, C H and Ernst, G and Ward, P D}
}
