Singh, V. (1999). `O` level text-book: Module III : business systems........... Asian pub.
芝加哥风格引文Singh, Vishun. `O` Level Text-book: Module III : Business Systems........... Delhi: Asian pub, 1999.
MLA引文Singh, Vishun. `O` Level Text-book: Module III : Business Systems........... Asian pub, 1999.
警告：这些引文格式不一定是100％准确.