You can locate videos in the IMC using the Reed-only library catalog. To browse Reed's collection of theatre videos, select 'Keyword' under the grey 'Search' heading. Search for 'theat* or stage' as a subject and limit your search to 'videos.'
International Dictionary of Theatre In three volumes: v.1. Plays.--v.2. Playwrights.--v.3. Actors, directors and designers. Reference PN2035 .I49 1992
Critical Survey of Drama Focuses on basic information re. dramatists, covering most nations and eras. Final volume includes an index for locating dramatists according to genre or era. Reference PN1625 .C68 2003.
The Columbia Encyclopedia of Modern Drama Entries for dramatists, plays, genres, etc. focusing on 1860-present. Also includes some entries for designers, directors, actors. Many entries with bibliographies. Reference PN1861 .C65 2007.
The World Encyclopedia of Contemporary Theatre Broad coverage of theatrical traditions worldwide, focusing on the 20th century. Reference PN1861 .W67 1994.
Encyclopedia of Asian Theatre Reference PN2860 .E53 2007
Modern Drama: Scholarship and Criticism, Charles A. Carpenter. Comprehensive bibliography in two volumes covering 'significant scholarship on all aspects of world drama since Ibsen.' For works published between 1966 and 1990. Reference PN1851 .C37.
Dictionary of Literary Biography Many of the volumes in this series address dramatists specifically- find biographical information, brief analysis of works and bibliography. See my list of the volumes covering dramatists.
Cambridge Collections Online Essays on major authors, literary genres, historic periods, and cultural movements, many of which include glossaries, timelines, and bibliographies. Good coverage for many significant playwrights.