Cita APA (7th ed.)

Hugo' s Simplified System. (1969). Italian in three months. Hugo's Language Books.

Cita Chicago (17th ed.)

Hugo' s Simplified System. Italian in Three Months. Londres: Hugo's Language Books, 1969.

Cita MLA (9th ed.)

Hugo' s Simplified System. Italian in Three Months. Hugo's Language Books, 1969.