@article{Greenwood1985,
author = {Greenwood, M.J.},
title= {Human migration: Theory, models, and empirical studies},
year = {1985},
doi = {10.1111/j.1467-9787.1985.tb00321.x},
journal = {Journal of Regional Science},
volume = {25},
number = {4},
pages = {521--544},
}