Simmonds, N. (1979). Principles of crop improvement. Longman.
Lua i Stíl Chicago (17ú heag.)Simmonds, N.W. Principles of Crop Improvement. Longman, 1979.
Lua MLA (8ú heag.)Simmonds, N.W. Principles of Crop Improvement. Longman, 1979.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.