Here you can find a list of the resources (and their information) used to create this site.
Tro, N. J. (2016). Principles of chemistry: A molecular approach (3rd ed.). Pearson Education.
On indicators: https://www.ch.ic.ac.uk/vchemlib/course/indi/indicator.html
On indicators: https://courses.lumenlearning.com/introchem/chapter/acid-base-indicators/
On the use of acids and bases: https://sciencing.com/uses-acids-bases-6824504.html.
On all of the definitions: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Acids_and_Bases/Acid
Specifically for the Arrhenius definition: https://www.intechopen.com/books/corrosion/the-arrhenius-acid-and-base-theory
For Bronsted-Lowry: https://courses.lumenlearning.com/suny-mcc-introductorychemistry/chapter/bronsted-lowry-acids-and-bases/
On Lewis bases: https://chemed.chem.purdue.edu/genchem/topicreview/bp/ch11/lewis.php
General acid-base information: https://www.khanacademy.org/science/chemistry/acids-and-bases-topic
General acid-base information: https://www2.nau.edu/lrm22/lessons/acids_and_bases/acids_and_bases.html
General acid-base information: https://courses.lumenlearning.com/boundless-chemistry/chapter/acids-and-bases/
And, of course, all of the various educational videos embedded within the site.
Thank you to the creators and sponsors of all these materials!