IFLA Cataloguing Section (Ed.). "FOREWORD TO THE THIRD EDITION" UNIMARC Manual. Berlin, Boston: Walter de Gruyter – K. G. Saur, 2009. 7-9. Web. Retrieved 23 May. 2013, from http://www.degruyter.com/view/books/9783598441820/9783598441820.7/9783598441820.7.xml

FOREWORD TO THE THIRD EDITION (2009). UNIMARC Manual (pp. 7-9). Berlin, Boston: Walter de Gruyter – K. G. Saur. Retrieved 23 May. 2013, from http://www.degruyter.com/view/books/9783598441820/9783598441820.7/9783598441820.7.xml

IFLA Cataloguing Section (Ed.). 2009. FOREWORD TO THE THIRD EDITION. In UNIMARC Manual, 7-9. Berlin, Boston: Walter de Gruyter – K. G. Saur. Retrieved 23 May. 2013, from http://www.degruyter.com/view/books/9783598441820/9783598441820.7/9783598441820.7.xml