Phonology deals with sound structure in language. While phonetics studies the physical properties of sounds, phonology concerns their mental representations. Phonology originated with the insight that much observable phonetic detail is irrelevant or predictable in language. This led to positing phonemes as minimal contrastive units, each comprising a collection of distinctive features. Later work went beyond this focus on surface contrast and re-conceived phonology as an aspect of speakers' mental grammars.
(From the entry for Phonology by Mary Paster in the International Encyclopedia of the Social & Behavioral Sciences, 2nd ed.)
Below are some key (online) reference works for phonology.
UBC Library, like most academic libraries, uses Library of Congress Subject Headings. Books on Phonology can be found in the UBC Library catalogue under these Subject Headings:
For books on the phonology of a specific language, use this format (replace 'French' with whichever language you are interested in):