See INTRODUCTIONS, Historical Resources, Further Reading: Italians of Southern California(e.g., Ricci, Trojani, etc.)
Italian Americans: Journals
Altreitalie: Rassegna internazional di studi sulle popolazioni di origine italiana nel mondo (International journal of the populations of Italian origin in the world), Fondazione Giovanni Agnelli
Italian Americana: Cultural and Historical Review
Italian American Review (CUNY)
Publications of the American Italian Historical Association (from annual meetings) http://www.aihaweb.org/
Ethnicity & Immigration
Alba, R., "The twilight of ethnicity among Americans of European ancestry: the case of Italians" Ethnic and Racial Studies, vol. 8, 1995: 134-159.
Daniels R., Coming to America, Perennial ed., New York, 2002.
Di Leonardo M., The Varieties of Ethnic Experience, Cornell University Press, New York, 1984.
Nelli, H., From immigrants to Ethnics: the Italian Americans, Oxford University Press, Oxford, New York, 1983.
Rolle, Andrew F., The American Italians: their history and culture, Belmont, Calif. : Wadsworth Pub. Co., 1972
_____The immigrant upraised; Italian adventurers and colonists in an expanding America, Norman : University of Oklahoma Press, 1968. [Gli emigrati vittoriosi. Translated by Quirino Maffi, Milano: Mondadori, 1972].
_____The Italian Americans : troubled roots, Norman : University of Oklahoma Press, 1984 [1980].
Other
Consult bibliographies and resource guides:
American Italian Historical Association (AIHA): http://www.aihaweb.org/
Cicala, John Allan, Italian American Folk Cultural Studies:
http://www-personal.umich.edu/~acicala/folk.html
Del Giudice, Luisa, "Bibliography of Italian American and Canadian Folklore," in Luisa Del Giudice, ed., Studies in Italian American Folklore, Logan: Utah University Press, 1993: 245-69.
Historical Society of Southern California: http://www.socalhistory.org/
National Institute of Statistics - Italy: http://www.istat.it/
National Italian American Foundation (NIAF): https://www.niaf.org/
Order of the Sons of Italy in America (OSIA): http://www.osia.org