Singh, V. (1999). `O` level text-book: Module III : business systems........... Asian pub.
Chicago Style (17th ed.) CitationSingh, Vishun. `O` Level Text-book: Module III : Business Systems........... Delhi: Asian pub, 1999.
MLA (9th ed.) CitationSingh, Vishun. `O` Level Text-book: Module III : Business Systems........... Asian pub, 1999.
Warning: These citations may not always be 100% accurate.