So I got a WH Smith gift card from my Grandmother for my Birthday and I decide to go looking for some of Mr Rankin's Books that I don't have in my waiting list yet. I go into the branch in Louth which is admittedly small and they have precisely none of them in. The following day I am in Skegness which is a slightly larger shop and once again, nada.
Today I am in Slough (away on business) and so I call in there and after a bit of searching find the "Fantasy/Horror" section and lo and behold there is one book, unfortunately it is "Hollow Chocolate Bunnies" which is already sat on the shelf at home awaiting my attention
A bit more poking about the shop did turn up a copy of "The Da-Da-De-Da-Da Code" nestled in with the Ian Rankin books (of which there were plenty to choose from) though so it wasn't an entirely fruitless exercise 
All the searching somehow makes actually finding the book all the more rewarding but why is Smith's selection so limited? I can remember picking up "Nostradamus ate my Hamster" some years back in the Kings Cross branch and there was definitely more of a selection then. Is it that Smith's really do give Robert his own shelf but don't tell anyone where it is? 

I seem to recall some years back WHSmiths removed ALL Robert's books from the shelves. Glad to see some are sneaking back though...
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Just have fun
I recall a similar joy of the hunt but with Otakars instead of Smith's.
I seem to be hunting ghosts at the moment; I just need to find the 1st editions of:
East of Ealing and the Brentford Triangle........I pace the streets of the North West and the internet highway but they still elude me.....maybe I need a raygun??!!?? 
You're most likely to find 1st editions of those early books on ebay or Abebooks - you just have to be patient, they do come up every now and then.
Waterstones and Borders usually have a pretty good selection of my stuff, but hey, why not just order the ones you want?
I was kind of stuck with Smiths unfortunately due to the whole gift-card thing, otherwise I'd normally get your books from Amazon or similar.
As an aside, I was once in a tiny independant Book shop in Padstow that had a larger selection than the three branches of Smiths I visited combined, t'was where I purchased The Brightonomnicon
I love shops like that, stuffed floor-to-ceiling with all sorts of interesting tomes. Reader's Rest in Lincoln is very similar. [/rambling comment]
If u live in Germany it is even harder
It was pretty tough getting all the German editions, because they are out of print. It took me some while, but now i have them all. But unfortunetly the translation is rather poor, so I had to buy them in English as well to really enjoy them. Another problem are the audio books... there is only one that was released in Germany and it seems that most of the english are not available either.
I have a German friend who reads Science Fiction, if he get's one he doesn't like he's never too sure if it's the book he doesn't like or the transtation that's not very good, so often reads the English version too
Well now I have a book shelf full of German and English Editions looks quite nice 
Take some pictures & show us here:
http://thegoldensprout.com/forum/527/show-us-your-shelves