Copeland, L. C. (1976). Principles of seed science and technology. National Book Store.
Lua i Stíl Chicago (17ú heag.)Copeland, Lawrence C. Principles of Seed Science and Technology. Manila: National Book Store, 1976.
Lua MLA (9ú heag.)Copeland, Lawrence C. Principles of Seed Science and Technology. National Book Store, 1976.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.