@book {1997,
	title = {Oorkondenboek van Holland en Zeeland tot 1299. IV. 1278 tot 1291},
	year = {1997},
	pages = {XVII+1003},
	publisher = {Van Gorcum},
	organization = {Van Gorcum},
	address = {Assen},
	keywords = {Tekstuitgave},
	issn = {90-232-3328-X},
	author = {Kruisheer, Jaap Gerardus}
}
@book {1992,
	title = {Oorkondenboek van Holland en Zeeland tot 1299. III. 1256 tot 1278},
	year = {1992},
	pages = {XVIII + 975},
	publisher = {Van Gorcum},
	organization = {Van Gorcum},
	address = {Assen},
	keywords = {Tekstuitgave},
	issn = {90-232-2692-5},
	author = {Kruisheer, Jaap Gerardus}
}
