@article{Claessens2009,
author = {Claessens, A. and Duncan, G. and Engel, M.},
title= {Kindergarten skills and fifth-grade achievement: Evidence from the ECLS-K},
year = {2009},
doi = {10.1016/j.econedurev.2008.09.003},
volume = {28},
number = {4},
pages = {415--427},
}