Source for older "Behind the Design" Books?

I’m just getting back into FIRST after being out of it for a few years, and I really want to try and buy some new copies of the 2 older “Behind the Design” books. Does anyone have a source for new copies of them?

In Particular
FIRST Robots: Aim High
FIRST Robots: Rack ‘N’ Roll: Behind the Design (FIRST Robots: Behind the Design)

The Aim High book seems easier to obtain with new listings on Amazon, but the Rack ‘N’ Roll book seems rare. Any suggestions are appreciated!

I got a rack n roll one 2ish years ago on Amazon. It was used, but in great condition!

Besides Amazon Ebay would be another option. You can set up a search that will email you if anything gets listed.