The two most common systems are the classification adopted by the website AmphibiaWeb, University of California, Berkeley, and the classification by herpetologist Darrel Frost and the American Museum of Natural History, available as the online reference database "Amphibian Species of the World".
ðə tˈuː mˈoʊst kˈɑːmən sˈɪstəmz ɑːɹ ðə klˌæsɪfɪkˈeɪʃən ɐdˈɑːptᵻd baɪ ðə wˈɛbsaɪt æmfˈɪbiə wˈɛb, jˌuːnɪvˈɜːsᵻɾi ʌv kˌælɪfˈoːɹniə, bˈɜːkli, ænd ðə klˌæsɪfɪkˈeɪʃən baɪ hˌɜːpɪtˈɑːlədʒˌɪst dˈæɹəl fɹˈɔst ænd ðɪ ɐmˈɛɹɪkən mjuːzˈiəm ʌv nˈætʃɚɹəl hˈɪstɚɹi, ɐvˈeɪləbəl æz ðɪ ˈɑːnlaɪn ɹˈɛfɹəns dˈeɪɾəbˌeɪs "æmfˈɪbiən spˈiːsiːz ʌvðə wˈɜːld".