Frog and Toad calls: https://musicofnature.com/calls-of-frogs-and-toads-of-the-northeast/
ODNR Reptile field guide: https://wildlife.ohiodnr.gov/portals/wildlife/pdfs/publications/id%20guides/pub354_Reptiles-opt.pdf
ODNR Amphibian field guide: https://wildlife.ohiodnr.gov/portals/wildlife/pdfs/publications/id%20guides/pub348.pdf
Conservation Status of Species: http://wildlife.ohiodnr.gov/portals/wildlife/pdfs/publications/information/pub356.pdf
Ohio Endangered Species: https://www.fws.gov/midwest/endangered/lists/ohio-spp.html