Reference books for JAA ATPL General Navagation

[Base leg]

Anyone know of a good book specifically written for the JAA ATPL General Navigation exam that makes easy reading ?

[aces low]

I used 'Pilot Navigation' which is very good at supporting the distance learning notes you may have. Sorry but can't remember author's name but you should be able to get it from Transair or Pilot Warehouse for about £20. Actually my PPSC notes were very good for general nav, but sometimes a different angle can be very helpful.