@article{Heckhausen1993,
author = {Heckhausen, J. and Krueger, J.},
title= {Developmental expectations for the self and most other people: Age grading in three functions of social comparison},
year = {1993},
doi = {10.1037//0012-1649.29.3.539},
volume = {29},
number = {3},
pages = {539--548},
}