National Association of Secondary School Principals. (1991). Tips for principals from NASSP: Tips: 1981 - 1989.
Chicago-Zitierstil (17. Ausg.)National Association of Secondary School Principals. Tips for Principals from NASSP: Tips: 1981 - 1989. Reston, Va, 1991.
MLA-Zitierstil (9. Ausg.)National Association of Secondary School Principals. Tips for Principals from NASSP: Tips: 1981 - 1989. 1991.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.