Cita APA (7th ed.)
(1980). A book of services. W. W. Norton.
Cita Chicago (17th ed.)
A Book of Services. Edinburg: W. W. Norton, 1980.
Cita MLA (9th ed.)
A Book of Services. W. W. Norton, 1980.
Atenció: Aquestes cites poden no estar 100% correctes.