Try:
http://www.guntherhall.com
It is an mail/internet order bookstore for everything coasters. They have all the coaster videos and almost every book on roller coasters/amusement parks. They are great, and the owner is the nicest person you want to meet.
If the book is in the Ingram/Books in Print database, then your local bookstore should be able to order it for you. Also you you ask them to order it for you, they might just start to carry it in their store.
Also try Amazon or BN.com, they are easier for small publisher to get into, so alot of smaller amusement parks books are on there.
Hope that helps!
-Andrew Hyde, Who HAS published an amusement park book and has several more in the works...
*** This post was edited by Andrew on 12/2/2001. ***