Acker, M. (2007). The passion-driven youth choir: A guide for directors of youth choirs with 10 to 100 members. Abingdon Press.
Chicago-Zitierstil (17. Ausg.)Acker, Martin. The Passion-driven Youth Choir: A Guide for Directors of Youth Choirs with 10 to 100 Members. Nashville: Abingdon Press, 2007.
MLA-Zitierstil (9. Ausg.)Acker, Martin. The Passion-driven Youth Choir: A Guide for Directors of Youth Choirs with 10 to 100 Members. Abingdon Press, 2007.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.