APA (7th ed.) Citation

British Museum. (1971). Catalogue of books printed in the XVth century now in the British Museum. Published by the Trustees of the British Museum.

Chicago Style (17th ed.) Citation

British Museum. Catalogue of Books Printed in the XVth Century Now in the British Museum. London: Published by the Trustees of the British Museum, 1971.

MLA (9th ed.) Citation

British Museum. Catalogue of Books Printed in the XVth Century Now in the British Museum. Published by the Trustees of the British Museum, 1971.