In addition to keyword searching, or searching by title and author, you may search Bobcat by subject heading, in order to make use of the catalog's controlled vocabulary. Subject headings are assigned to published material by the Library of Congress. They can be very broad, consisting of one word, for example, literature or folklore or mythology, but they also tend to link terms together, specifying what a work is about according to theme, period, geographical region, etc.
In general, if you are looking for criticism related to an individual (writer, performer, artist, etc), you can add a hyphen to the person's name and attach criticism and interpretation, then search as a subject heading. If you are looking for criticism of a theme or literary or artistic movement, you can attach the phrase history and criticism. For example:
You could also do a keyword search, combining the terms fairy tales and criticism, both as subject heading terms.