Spotlight on Legal Immigration to the United States / Migration Policy Institute, November 2007
http://www.migrationinformation.org/USfocus/display.cfm?id=651
Gretchen Reinemeyer and Jeanne Batalova
"This updated Spotlight takes a close look at the 2006 statistics on foreign nationals admitted for/those who adjusted to lawful permanent residence (LPR). One of the most commonly used publications on US immigration statistics is the Yearbook of Immigration Statistics, published by the Department of Homeland Security's Office of Immigration Statistics."