Overview of Operating Systems: Sources

Bell, John T. "Introduction." University of Illinois, Chicago, Accessed 11 July 2022. URL: https://www.cs.uic.edu/~jbell/CourseNotes/OperatingSystems/1_Introduction.html

Chapter 4: The Operating System.
Wienand, Ian (2019). Computer Science from the Bottom Up. This work is licensed under the Creative Commons Attribution-ShareAlike3.0 Unported License. URL: https://www.bottomupcs.com/csbu.pdf