hɪz kˌɑːntɹɪbjˈuːʃənz tə θiəɹˈɛɾɪkəl klædˈɪstɪks, sˈʌtʃ ɐz hɪz nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi wˈʌn bˈʊk, sˌɪstəmˈæɾɪks ænd bˌaɪoʊdʒɪˈɑːɡɹəfi: klædˈɪstɪks ænd vˈɪkɐɹˌiəns kˌoʊˈɔːθɚd wɪð ɡˈæɹəθ nˈɛlsən, ɑːɹ ˈɔːlsoʊ hˈaɪli ɹᵻɡˈɑːɹdᵻd.
His contributions to theoretical cladistics, such as his 1981 book, Systematics and Biogeography: Cladistics and Vicariance (coauthored with Gareth Nelson), are also highly regarded.