Lewis, R. H. (1993). A Due V: For Soprano & Piano - für Sopran & Klavier 1987 / Robert Hall Lewis. Doblinger.
Cita Chicago (17th ed.)Lewis, Robert Hall. A Due V: For Soprano & Piano - Für Sopran & Klavier 1987 / Robert Hall Lewis. Wien: Doblinger, 1993.
Cita MLA (8th ed.)Lewis, Robert Hall. A Due V: For Soprano & Piano - Für Sopran & Klavier 1987 / Robert Hall Lewis. Doblinger, 1993.
Atenció: Aquestes cites poden no estar 100% correctes.