Brooks, C. A., & Sims, R. (2015). Roland Hayes: The legacy of an American tenor. Indiana University Press.
Lua i Stíl Chicago (17ú heag.)Brooks, Christopher Antonio, agus Robert Sims. Roland Hayes: The Legacy of an American Tenor. Bloomington, Indiana: Indiana University Press, 2015.
Lua MLA (9ú heag.)Brooks, Christopher Antonio, agus Robert Sims. Roland Hayes: The Legacy of an American Tenor. Indiana University Press, 2015.
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