[digital vocal score] Fidelio : an opera in two acts

MLA

Van Beethoven, Ludwig, et al. [digital Vocal Score] Fidelio : an Opera In Two Acts. New York: Schirmer, 1935.

APA

Van Beethoven, L., Baker, T., Bouilly, J., Krehbiel, H. E, & Sonnleithner, J. (1935). [digital vocal score] Fidelio : an opera in two acts. New York: Schirmer.

Chicago

Van Beethoven, Ludwig, Theodore Baker, Jean-Nicolas Bouilly, H. E Krehbiel, and Joseph Sonnleithner. [digital Vocal Score] Fidelio: An Opera In Two Acts. New York: Schirmer, 1935.