Consult the series page on the university press website for information about who to contact and what materials to include for the submission. Series may have specific requirements about the type and format of materials querying authors should submit, and they may ask for a short explanation of how a project fits into the series. In general, your primary contact will be the acquiring editor for the series, although some presses may also list the contact information for the series editor(s). You may email the acquiring editor directly, indicating your interest in a particular series. The acquiring editor can then share your inquiry with the series editor(s).
—University of Arizona Press, November 2022
See also “How do I know if a book series is a good fit for my project?”.