"Definition of software bus". PCMAG. Retrieved 2021-06-29. https://www.pcmag.com/encyclopedia/term/software-bus
Clarke, A.; Eaton, J. M.; David, D. Powys Lybbe (October 26, 1983). CP/M - the Software Bus: A Programmer's Companion. Sigma Press. ISBN 978-0905104188. 978-0905104188
Johnson, Herbert R. (July 30, 2014). "CP/M and Digital Research Inc. (DRI) History". https://retrotechnology.com/dri/d_dri_history.html
Duncan, Ray (1988). The MS-DOS Encyclopedia. Microsoft Press. p. 27. Further complications arose when Lifeboat Associates agreed to help promote MS-DOS but decided to call the operating system Software Bus 86. MS-DOS thus became one of a line of trademarked Software Bus products, another of which was a product called SB-80, Lifeboat's version of CP/M-80. https://books.google.com/books?id=fVEPAQAAMAAJ&q=%22Software+bus%22