Library of Congress. Network Development and MARC Standards Office., Library and Archives Canada. Standards and Support., British Library. Bibliographic Standards and Systems., National Library of Canada. Standards and Support., & British Library. National Bibliographic Service. (1999). MARC 21 format for bibliographic data: Including guidelines for content designation (1999 ed.). Washington : Ottawa: Library of Congress, Cataloging Distribution Service ; Library and Archives Canada.

Library of Congress. Network Development and MARC Standards Office., Library and Archives Canada. Standards and Support, British Library. Bibliographic Standards and Systems, National Library of Canada. Standards and Support, and British Library. National Bibliographic Service. MARC 21 Format for Bibliographic Data: Including Guidelines for Content Designation. 1999 ed. Washington : Ottawa: Library of Congress, Cataloging Distribution Service ; Library and Archives Canada, 1999.

Library of Congress. Network Development and MARC Standards Office., et al. MARC 21 Format for Bibliographic Data: Including Guidelines for Content Designation. 1999 ed. Washington : Ottawa: Library of Congress, Cataloging Distribution Service ; Library and Archives Canada, 1999.