ZIMMERMAN, J. D. Irrigation. John Wiley & Sons.
Lua i Stíl Chicago (17ú heag.)ZIMMERMAN, JOSEP D. Irrigation. John Wiley & Sons.
Lua MLA (8ú heag.)ZIMMERMAN, JOSEP D. Irrigation. John Wiley & Sons.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.