APA

Billings W., David H. T., . (1947). Modern Music for four mixed voices. New York: Music Press.

Chicago

Billings William, David Hans Theodore, . 1947. Modern Music for four mixed voices. New York: Music Press.

Harvard

Billings W., David H. T., . (1947). Modern Music for four mixed voices. New York: Music Press.

MLA

Billings William, David Hans Theodore, . Modern Music for four mixed voices. New York: Music Press. 1947.