(1998). Null set / Andrew Robbins.
Cita Chicago (17th ed.)Null Set / Andrew Robbins. 1998.
Cita MLA (9th ed.)Null Set / Andrew Robbins. 1998.
Atenció: Aquestes cites poden no estar 100% correctes.
Cita APA (7th ed.)
(1998). Null set / Andrew Robbins.
Cita Chicago (17th ed.)Null Set / Andrew Robbins. 1998.
Cita MLA (9th ed.)Null Set / Andrew Robbins. 1998.