NOTOTPTU

https://bretionly.github.io/ertrASAS/BOOK1.html

https://bretionly.github.io/ertrASAS/BOOK2.html

https://bretionly.github.io/ertrASAS/BOOK3.html

https://bretionly.github.io/ertrASAS/BOOK4.html

https://bretionly.github.io/ertrASAS/BOOK5.html