Williams, G. Biology for you (New national curriculum edition for GCSE.).
Lua i Stíl Chicago (17ú heag.)Williams, Gareth. Biology for You. New national curriculum edition for GCSE.
Lua MLA (8ú heag.)Williams, Gareth. Biology for You. New national curriculum edition for GCSE.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.