Second hand books I've bought

Of all the second hand gardening books you’ve brought, which have you found most useful ?

Very few of them! Nobody gardens my way.
Joy Larkcom's "Grow your own vegetables" for basic essential information - like when to sow, spacing etc. No pictures, just words. 
I like books about Forest gardening,  perennial veg, polyculture, herbs.
Books with the words Design & Plan in the titles have no chance. Not a fan of TV gardeners although Bob Flowerdew and Geoff Hamilton are OK.
I'm not a fan of No Dig Charles either. All his books have the same information, jiggled about and regurgitated.                                                                                .

You have mentioned the only two gardeners I used to follow! Sadly Geoff Hamilton is no longer with us  and I haven't heard a peep from Bob Flowerdew for a while? Both were down to earth gardeners but Geoff was very middle class wherea Bob struck a note with my Council house mentality!