@article{Andersen2016,
author = {Andersen, S.C. and Humlum, M.K. and Nandrup, A.B.},
title= {Increasing instruction time in school does increase learning},
year = {2016},
doi = {10.1073/pnas.1516686113},
volume = {113},
number = {27},
pages = {7481‒7484},
}