The MLA International Bibliography and ABELL (Annual Bibliography of English Language and Literature) databases also include listings for book-length critical works. If you find a book that looks good, use the 
button or search directly in Duke Libraries' online catalog for these titles.
Literature Criticism Online a compendium of critical essays from classical to contemporary periods, good coverage of "canonical" works
MLA International Bibliography core literature database, indexes articles and books
Bibliography of Asian Studies interdisciplinary, good coverage of literature and film
GenderWatch journal articles from women's and gender studies
ProQuest click tab at top of results list to limit to scholarly sources
Stuck? Ask a Librarian!
A Companion to Asian American Studies by 
A Companion to Global Gender History by 
Encyclopedia of Sex and Gender by 
Handbook of Feminist Research by 
The Oxford Handbook of American Women's and Gender History by 
Oxford Handbook of Feminist Philosophy by 
The Routledge Companion to Postcolonial Studies by 
The SAGE Handbook of Feminist Theory by Search for entries on critics and theorists, critical schools and movements, and the critical and theoretical innovations of specific countries and historical periods
