https://www.norwegiancreations.com/2017/10/an-intro-to-boolean-algebra-and-logic-gates-part-1/

https://en.wikipedia.org/wiki/Boolean_algebra

https://ece.uwaterloo.ca/~msachdev/ECE223/Overhead Slides/ECE 223 Boolean Algebra.pdf

http://www.ee.ncu.edu.tw/~jimmy/courses/DCS04/chap_2.pdf

https://homepage.cs.uiowa.edu/~ghosh/3A.ppt

https://www.cambridgeinternational.org/Images/285024-topic-3.3.2-boolean-algebra-9608-.pdf

https://www2.southeastern.edu/Academics/Faculty/kyang/2018/Spring/CMPS375/ClassNotes/CMPS375ClassNotesChap03.pdf

http://faculty.kfupm.edu.sa/EE/ahussain/teaching/EE200_Exp_02.pdf

http://ebooks.bharathuniv.ac.in/gdlc1/gdlc1/Engineering Merged Library v3.0/GDLC/Number Systems, Boolean Algebra and Logic Gates (7459)/Number Systems, Boolean Algebra and Logic Gates - GDLC.pdf

http://web.mit.edu/6.131/www/document/7400.pdf

http://www.ee.surrey.ac.uk/Projects/CAL/digital-logic/combindex.html