Hippopotamus amphibius - Lisa Frisch provides information on this mammal, its classification, habitat, adaptations, nutrition and reproduction. - http://acadweb.uwlax.edu/07Spring/SAH/BIO203/frisch_lisa/
World Conservation Union (IUCN) Hippo Specialists Group - Promotes scientifically-based action for the conservation of common and pygmy hippos. Includes conservation news, research, facts, and statistics. - http://moray.ml.duke.edu/projects/hippos/