Hi, I see you say that you are located on an island, so my bet is that your local library is not well stocked with PPL books... However you can ask any library for an 'Inter-Library Loan' where they will obtain any book you require from the national stock.
I used to plague my local library for Gliding Books on loan, and even had them buy in some of the latest Radio Theory books.
Make sure you get the right ones however, as I spent days learning about Astro-Navigation with a Sextant, and how to calculate distances from Lat / Long. All of which was more relevant to Atlantic Shipping than Aeronautics.
Best of luck... Pete