Neal Hellman's dulcimer chord book published by Mel Bay used to be the standard.  I don't change tunings that much, so I never had a use for it, but you can still find new and used copies all over the place.  Here it is directly from Mel Bay: https://www.melbay.com/Products/94662/dulcimer-chord-book.aspx .  It was printed in a long, narrow format to fit in a dulcimer case.

--
Dusty T., Northern California
Site Moderator

As a musician, you have to keep one foot back in the past and one foot forward into the future.
-- Dizzy Gillespie

This is an e-book, so you have to download and print it out yourself. However, it has everything you need to know about mountain dulcimer chords. https://www.melbay.com/Products/93858EB/dulcimer-chord-encyclopedia.aspx?classificationSId=D09

Ken

"The dulcimer sings a sweet song."

https://folkcraft.com/products/neal-hellman-dulcimer-chord-book

 Can anyone suggest a good book for chords? hopefully with more than just Dad, A book that has a good combination of different tuning and with more than just three or four Combinations of a particular court .

Hope this makes sense