Broken Homes - Ben Aaronovitch

I like to have all my books in a series in one edition (which was quite a challenge with ASOIAF but I made it).

 

I always expected it would not be a problem with the Rivers of London series, as I had found the first three books without any problem. So, when Broken Homes was published, I just thought I'd just wait for 'my' edition (height about 19,8 cm), but we're three quarters of a year further now, and I still can't find any sign of it. There are many paperback, 17 cm or 21 cm, what was wrong with the edition I wanted.

 

Has anyone, who like me is a bit neurotic when it comes to getting the right edition, perhaps noticed the 19,8-ish paperback edition of Broken Homes by Ben Aaronovitch?

(I've check BookDepository and a Dutch retailer (and a big German bookshop), but couldn't find it. Still, I might have just overlooked it...)