3Howard Dodson and Sylviane A. Diouf. In Motion: The African- American Migration Experience [ M/OL ]. Published by National Geographic, 2005. http://www.nypl. org.
4Brad Knicherbocker. US Population 300 Million: Part 1 - Is a Bigger Nation Richer? [ N]. The Christian Science Monitor, September 12, 2006. http.//www.csmonitor. ocm.
5Marc Perry & Paul Mackun. Population Change and Distribution:1990 to 2000[Z]. April 2001. http://www. census. gov.
6U. S. Census Bureau. Statistical Abstract of the United States- 1980 [ R ]. Statistical Abstract of the UnitedStates: 2000[ R}. http://www.census.gov.
7Annual immigration to the United States: The real numbers. may. 2007, No. 16. http://www. migrationpolicy. org.
8赵广俊.赴美生子潮晃动国籍出生地原则[N].法制日报,2007-09-03(3).
9Alexander B. Callow. American Urban History: An Interpretive Reader with Commentaries[ M]. Third Edition. London: Oxford University Press, 1982 : 263.
10Howard P. Chudacoff & Judith E. Smith. The Evolution of America Urban Society[ M]. Third Edition. Englewood Cliffs, New Jersey: Prentice Hall, 1988. 152.
