* الضفدع الحقيقي* Herps of Texas: "Rana catesbeiana"* British Columbia Frog Watch Program: Bull Frog Fact Sheet* Bullfrog at allaboutfrogs.com* Bullfrog recordings* application.
== References ====External links==* Herps of Texas: "Rana catesbeiana"* British Columbia Frog Watch Program: Bull Frog Fact Sheet* Bullfrog at allaboutfrogs.com* Bullfrog at the Global Invasive Species Database* Bullfrog recordings