The present study focuses on the importance of see and see also references on the catalogs of the Mosul University library An importance is given to name and author headings in particular . The study also covers the effects of neglecting the use of such types of cross references on the efficiency of the library catalogs specially when there is no cross relations made between different forms of reference to the same heading The researcher sees that the use of logic cross references in types and number will increase the efficiency of the library catalog in retrieval .