My publisher First Second Books has posted a short preview of City of Spies on their website here: http://www.firstsecondbooks.com/cityofspies/cityofspies.html
Sadly, the images are a little small/lo-res which makes the text a bit hard to read at places, but I suppose that’s just all the more incentive to get the book when it comes out.

(As a reminder, you can also see some sample pages (different ones than at the above link) on my site, here: http://dizin-art.com/cityofspies.html)