Reference books with literary criticism will be in a variety of call numbers, depending on genre, time period, and nationality of the author, but most will be in the P call number range. Books that cover literature from multiple countries will be in PN -- some examples:
- Contemporary literary criticism - REF. PN771 .C62
- Twentieth-century literary criticism - REF. PN94 .T93
- Nineteenth-century literature criticism - REF. PN761 .N5
- Contemporary authors - REF. PN451 .C6 (also New Revision series, immediately following on shelf)
- Short story criticism - REF. PN3321 .S56
- Classic cult fiction: a companion to popular cult literature - REF. PN3340 .W48 1992
Books on British literature are in PR:
- British writers - REF. PR85 .B688
- Shakespearean criticism - REF. PR2965 .S43
- Gothic literature - PR408.G68 G675 2006
Books on American literature are in PS:
- American writers classics - REF. PS129 .A56
- Asian American literature : reviews and criticism of works by American writers of Asian descent - REF. PS153.A84 A82 1999
- Black literature criticism : classic and emerging authors since 1950 - REF. PS153.N5 B556 2008
- American nature writers - REF. PS163 .A6 1996
For criticism on children's books, try these in PN and Z:
- Children’s literature review - REF. PN1009.A1 C5139
- Something about the author - REF. PN451 .S6
- Children’s literature : a guide to the criticism - REF. Z1037 .H46 1987
To find initial critical impressions of older books, try the book review indexes in Z:
- Book review index (1965-2014) - REF. Z1035.A1 B6
- Book review digest (1905-2014) - REF. Z1219 .C95
- The New York times book review index, 1896-1970 - REF. Z1035 .N48 Index
Black Literature Criticism by 
Gothic Literature by 
Classic Cult Fiction by