Providing the books are included in your Medium Verified Book Authors program and appear as Featured Books, we can list as many as there are. Please check with the artist, @danielwilliams737, about including his images in your coloring book, though you can include the image I provided along with my drabble wherever the drabble is published. I'll be happy if he approves. Sometimes, he doesn't reply immediately; he's a writing teacher and a college and busy. But so far he does reply to me.