Cita APA (7th ed.)

Singh, V. (1999). `O` level text-book: Module III : business systems........... Asian pub.

Cita Chicago (17th ed.)

Singh, Vishun. `O` Level Text-book: Module III : Business Systems........... Delhi: Asian pub, 1999.

Cita MLA (9th ed.)

Singh, Vishun. `O` Level Text-book: Module III : Business Systems........... Asian pub, 1999.