The tempest :
opera in three acts /
music by John Eaton ; libretto, after Shakespeare by Andrew Porter.

APA Citation

Eaton, J., Porter, A., Shakespeare, W. (1985). The tempest: opera in three acts. New York: G. Schirmer.

MLA Citation

Eaton, John, 1935-2015, Andrew Porter, and William Shakespeare. The Tempest: Opera In Three Acts. New York: G. Schirmer, 1985.

Warning: These citations may not always be complete (especially for serials).