@inbook{Wardwell1980,
author = {Wardwell, John M.},
title= {Toward a Theory of Urban–Rural Migration in the Developed World},
year = {1980},
doi = {10.1016/B978-0-12-136380-2.50012-7},
editor = {Brown, D.L.},
editor = {Wardwell, John M.},
booktitle = {New Directions in Urban–Rural Migration},
address = {New York},
publisher = {Academic Press},
pages = {71--114},
}