What is the author's name for the original supernatural book series?

[Supernatural-Winchesters]

I absolutely luv the show Supernatural but i know there was a book series that the show was based off of but i cant find the actual author because the episode 'The monster at the end of this book' says a name but its not the actual author. So does anyone know it?

 

[Brandon]

Supernatural: John winchester's journal by Alex Irvine http://www.amazon.com/gp/aw/d.html/ref=mp_s_a_1/176-7947010-0218044?qid=1239477463&a=0061706620&sr=1-1.. Supernatural: bone key by keith R.a decandido http://www.amazon.com/gp/aw/d.html/ref=mp_s_a_2/176-7947010-0218044?qid=1239477463&a=0061435031&sr=1-2