Indiana University: Thesaurus Musicarum Latinarum
Medieval.org: Medieval Music & Arts Foundation
Petrucci Music Library: People from the Medieval Era
Petrucci Music Library: People from the Renaissance Era
International Musicological Society "Cantus Planus" Study Group
Early Music in Columbus
The Plainsong and Medieval Music Society
The Orlando Consort
Journal of Seventeenth-Century Music
University of Michigan: Renaissance Liturgical Imprints: A Census
The Altramar Medieval Music Ensemble