Walliser, O. H. (1986). Global bio-events: A critical approach. Springer-Verlag.
Lua i Stíl Chicago (17ú heag.)Walliser, Otto H. Global Bio-events: A Critical Approach. Berlin ; New York: Springer-Verlag, 1986.
Lua MLA (9ú heag.)Walliser, Otto H. Global Bio-events: A Critical Approach. Springer-Verlag, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
