Geissmann, T. (1993). Evolution of communication in gibbons (Hylobatidae). Universität Zürich.
Lua i Stíl Chicago (17ú heag.)Geissmann, Thomas. Evolution of Communication in Gibbons (Hylobatidae). Switzerland: Universität Zürich, 1993.
Lua MLA (8ú heag.)Geissmann, Thomas. Evolution of Communication in Gibbons (Hylobatidae). Universität Zürich, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.