@book{15558,
	author = {Gibson, J. B. and Sobin, L. H.},
	title = {Histological typing of tumours of the liver, biliary tract and pancreas.},
	publisher = {World Health Organization,},
	year = {1978.},
	series = {INTERNATIONAL histological classification of tumours ; no. 20).},
	address = {Geneva : }
}