I think yellow pages and yell.com could be worth a punt again at the right price.
The book because as Allan says the older generation still use it, The grey pound as I call them.
Yell.com do very well in the organic listings, the problem being "IF" people do click they are presented with a list of names and numbers, being top of this list is very expensive the next price bracket down i believe work on a rotation system.
Some people like a list of name and numbers as opposed to clicking on individual websites, price shoppers and sales people especially
Like i say though maybe worth a punt at the right price.