What the Buddha Taught (by Walpola Rahula Thero)
Read more & sources:
https://sites.google.com/site/rahulawhatthebuddha/
http://ftp.budaedu.org/ebooks/pdf/EN132.pdf
http://www.ahandfulofleaves.org/documents/What%20the%20Buddha%20Taught_Rahula.pdf
https://www.academia.edu/8981479/Dr_Walpola_Rahula_What_the_Buddha_Taught
http://www.khamkoo.com/uploads/9/0/0/4/9004485/what_the_buddha_thought.pdf