@misc{U.S. Census Bureau1993a,
author = {U.S. Census Bureau},
title= {Census of Population and Housing, 1990 [United States]: Public Use Microdata Sample: 5-Percent Sample },
year = {1993a},
doi = {10.3886/ICPSR09952},
publisher = {U.S. Census Bureau},
address = {Washington},
}