Barnes and Noble has all four books on one easy-to-access page.  Click on the link below, and you'll be taken to that page!

Diablo's Shadow available at Diesel ebooks.

Orders for Bookstores and Libraries

Bookstores and Libraries can order Diablo's Shadow (Night Shadows Press) from Ingram Book Company

Diablo's Shadow will be carried at local booksellers:

Tattered Cover 

LoDo, Colfax and Highlands Ranch locations