https://www.youtube.com/watch?v=POjnw0xEVas
Flex & Bison Tutorial: Part 1 - Basics

https://www.youtube.com/watch?v=pu0hX5lftQU
Flex & Bison Tutorial: Part 2 - Flex Code

https://www.youtube.com/watch?v=ueZ9LX1xItQ
Flex & Bison Tutorial: Part 3 - Bison Code

https://www.youtube.com/watch?v=WdAS6OehGPE
Flex & Bison Tutorial: Part 4 - Grammar

https://www.youtube.com/watch?v=6a-8IVFYHGg
Flex & Bison Tutorial: Part 5 - Grammar and Bison Code

https://www.youtube.com/watch?v=0MUULWzswQE
Setup and Run Lex and YACC code in Windows (Flex, Bison)