Gaya APA

HORACEK, L, , A, L, G. (1970). Programed Ear Training Volume 1 Intervals . New York: Harcourt.

Gaya MLA

HORACEK, Leo, , And, LETKOPFF,, Gerald. "Programed Ear Training Volume 1 Intervals". New York: Harcourt, 1970. BUKU.