APA
Hanushek E. A., National Bureau of Economic Research, Ruhose J. & Woessmann L. (2015). Human capital quality and aggregate income differences. Cambridge: NBER.
Chicago
Hanushek Eric A, National Bureau of Economic Research, Ruhose Jens and Woessmann Ludger. 2015. Human capital quality and aggregate income differences. Cambridge: NBER.
Harvard
Hanushek E. A., National Bureau of Economic Research, Ruhose J. and Woessmann L. (2015). Human capital quality and aggregate income differences. Cambridge: NBER.
MLA
Hanushek Eric A, National Bureau of Economic Research, Ruhose Jens and Woessmann Ludger. Human capital quality and aggregate income differences. Cambridge: NBER. 2015.