@article{Frey1996,
author = {Frey, W.H. },
title= {Immigration, domestic migration, and demographic balkanization in America: New evidence for the 1990s},
year = {1996},
doi = {10.2307/2137808},
journal = {Population and Development Review },
volume = {22},
number = {4},
pages = {741−763},
}