This resource is the International Harp Archives at Brigham Young University. The site includes access to the BYU catalog for searching about harp and other music, a harp music of the 18th and 19th century wiki and database, which includes access to public domain harp music, and a collection of finding aids. Users can also request reproductions (for a fee) and this library is also an American Harp Association lending library for those that are members.
The Sibley Music Library at the University of Rochester has a section in the rare books and music collection dedicated to the harp. This list includes all harp resources available within the special collection, including cataloged items in the rare books collection, the Lucile Johnson Rosenbloom Collection of printed music and manuscripts, the Nan Gullo collection, and the Henry B. Neejer collection.
This online resource offers links and information regarding the harp.
Rensch, Roslyn. The Harp, from Tara's halls to the American schools. New York: Philosophical Library, 1950.
MUSIC STACKS ML1005.R4
This book covers the history of the harp in ancient times, the movement of the harp into Europe, the pedal harp, a selected bibliography and index, and selected composers, compositions, and recordings for the harp.
Schechter, John Mendell. The Indispensable Harp : Historical Development, Modern Roles, Configurations, and Performance Practices in Ecuador and Latin America. Kent, Ohio: Kent State University Press, 1992.
MUSIC STACKS ML1005.S26 1992
Includes bibliographical references (p. 270-281) and index.