Chamberlain, C. Gymnosperms: Structure and evolution.
Lua i Stíl Chicago (17ú heag.)Chamberlain, Charles. Gymnosperms: Structure and Evolution.
Lua MLA (9ú heag.)Chamberlain, Charles. Gymnosperms: Structure and Evolution.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.