Cita APA (7th ed.)

Abt, F. (1921). Practical singing tutor for soprano or tenor. G. Schirmer.

Cita Chicago (17th ed.)

Abt, Franz. Practical Singing Tutor for Soprano or Tenor. Nueva York: G. Schirmer, 1921.

Cita MLA (9th ed.)

Abt, Franz. Practical Singing Tutor for Soprano or Tenor. G. Schirmer, 1921.