@article{Psacharopoulos2004,
author = {Psacharopoulos, G. and Patrinos, H.A. },
title= {Returns to Investment in Education: A Further Update},
year = {2004},
doi = {10.1080/0964529042000239140},
journal = {Education Economics },
volume = {12},
number = {2},
pages = {111--134},
}