Where to find copies of pitch bibles?

Hey there,

Does anyone know where it's possible to find copies of animation series pitch bibles (either free OR for sale) ?

Looking online, it seems like I can occasionally get lucky and find random examples, but I'm really looking for an example of a pitch bible for a show with a strong and involved cartooniverse (i.e. fantasy, sci-fi, or something else with a LOT of detail to be covered).

Any ideas? Thanks!

~ Nicholai