APA (7th ed.) Citation

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 Style (17th ed.) Citation

Clotfelter, Charles T., Helen F. Ladd, and Jacob L. Vigdor. How and Why Do Teacher Credentials Matter for Student Achievement? Cambridge, Mass: National Bureau of Economic Research, 2007.

MLA (9th ed.) Citation

Clotfelter, Charles T., et al. How and Why Do Teacher Credentials Matter for Student Achievement? National Bureau of Economic Research, 2007.