Learning more about Pratchett and his writing style

I always loved how nobody can make a dialogue so fun and real like Terry, both with how he can set a character but then write the dialogue so accurate to the character.

I always thought that if i were to ever write a book, i would love to inspire it by his writing style. Could you recommend me anything like documentaries or studies or even uni essays about Pratchett or about Discworld?

Also sorry no idea what flair should i put this under.