1. Birds, law of battle Publication: Bethesda, MD : U.S. National Library of Medicine, National Institutes of Health, Health & Human Services, 2009 Subject(s): Birds -- anatomy & histologyCompetitive Behavior -- physiology
2. Mammals, law of battle Publication: Bethesda, MD : U.S. National Library of Medicine, National Institutes of Health, Health & Human Services, 2009 Subject(s): Antelopes -- anatomy & histologyHorns -- anatomy & histologyCompetitive Behavior -- physiology