That question gets asked of me almost every day. Turns out, Boathouse Mouse is just about everywhere! At least the ability to purchase A New Adventure, A New Name is everywhere.
So here are a few of the simplest sources.
1) Shawna's Etsy store.
2) Amazon. They are everywhere.
3) Your locally owned book store. If you are fortunate enough to have a good book store in your community, please check with them.