abebooks
Trigger: !abebooks
Try it
Kagi would openhttps://www.abebooks.com/servlet/SearchResults?kn=music+theory
Run @abebooks in Kagi for Kagi's own results from www.abebooks.com only
URL pattern: https://www.abebooks.com/servlet/SearchResults?kn=query
Searches www.abebooks.com, filed under Learning.