@book {2000,
	title = {Frieslands oudheid. Het rijk van de Friese koningen, opkomst en ondergang},
	year = {2000},
	pages = {408},
	publisher = {Matrijs},
	organization = {Matrijs},
	address = {Utrecht},
	issn = {90-5345-167-6},
	author = {Halbertsma, Herre}
}
