Web. 3 (Mafia, also Maffia) https://es.wikipedia.org/wiki/Mafia https://es.wikipedia.org/wiki/Cosa_nostra

Random House (Mafia or Maffia)

World Book encyclopedia, 2010: v. 13, p. 41 (Mafia; a secret criminal society in Sicily; also used as a general term for any underworld criminal organization)

Encyclopedia Americana, 2005: v. 18, p. 75 (Mafia; a name applied to criminal associations in Sicily and organized crime gangs in the United States; the Sicilian Mafia "has always been an alliance of many small, semiautonomous groups")

FBI website, viewed on July 19, 2016: what we investigate, organized crime (Mafia; "Italian criminal societies known as the Mafia"; groups include the Sicilian Mafia, Camorra, 'Ndrangheta, and Sacra Corona Unita)