Clotfelter, C. T., Ladd, H. F., & Vigdor, J. L. (2007). How and why do teacher credentials matter for student achievement? National Bureau of Economic Research.
Chicago-Zitierstil (17. Ausg.)Clotfelter, Charles T., Helen F. Ladd, und Jacob L. Vigdor. How and Why Do Teacher Credentials Matter for Student Achievement? Cambridge, Mass: National Bureau of Economic Research, 2007.
MLA-Zitierstil (9. Ausg.)Clotfelter, Charles T., et al. How and Why Do Teacher Credentials Matter for Student Achievement? National Bureau of Economic Research, 2007.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.