Ferguson, J. H. (1973). American federal government (12th ed.). McGraw-Hill.
Chicago Style aipamenaFerguson, John H. American Federal Government. 12th ed. New York: McGraw-Hill, 1973.
MLA aipamenaFerguson, John H. American Federal Government. 12th ed. McGraw-Hill, 1973.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.