Five go off to camp
Five go off in a caravan
Five have a wonderful time.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
The Famous Five special by Enid Blyton. Published by Hodder & Stoughton in 1959. Publication and catalogue information, links to buy online and reader comments.
obnb.uk is a Good Stuff website.