I'm the author of the ASHFALL three-and-a-half-ology: ASHFALL, ASHEN WINTER, SUNRISE, and DARLA'S STORY.
I picked 6 out of 20 bookstores that I personally find most appealing for my eyes. Rest of the amazing bookstores you can find behind the link.
Cook & Book, Brussels, Belgium
Poplar Kid’s Republic, Beijing, China
Cafebreria El Pendulo, Mexico City, Mexico
Bart’s Books, Ojai, California
Corso Como Bookshop, Milan, Italy
VVG Something, Taipei, Taiwan