@article{Frey2005,
author = {Frey, W.H. and Liaw, K.L. },
title= {Migration within the United States: Role of race-ethnicity},
year = {2005},
doi = {10.1353/urb.2006.0004},
journal = {Brookings-Wharton Papers on Urban Affairs },
volume = {6},
pages = {207--262},
}