W Holdings of the core scholarly literature of the field are reasonably solid from the mid-19th century to the late 1970's, including standard reference works and full runs of all major journals and of many major archaeological reports series. Much of this material has not been superseded and is still being used actively today.
Coverage declines abruptly after ca.
1980, with major gaps in monographs, journals and report series. Many important monographic series started after 1980 are absent, as are reports of major excavations and catalogs of major museum collections. This is the case with publications from all major European countries. Publications from present day Middle Eastern countries, especially in the respective vernacular languages, are hardly represented at all. As a result, existing gaps are perpetuated and new ones continually formed.