Henry Baldwin Ward, G. C. W. Fresh water biology. John Wiley and Sons.
Lua i Stíl Chicago (17ú heag.)Henry Baldwin Ward, George Chandler Whipple. Fresh Water Biology. John Wiley and Sons.
Lua MLA (8ú heag.)Henry Baldwin Ward, George Chandler Whipple. Fresh Water Biology. John Wiley and Sons.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.