Portmann, A. Animal forms and patterns: A study of the appearance of animals.
Citazione stile Chigago Style (17a edizione)Portmann, Adolf. Animal Forms and Patterns: A Study of the Appearance of Animals.
Citatione MLA (9a ed.)Portmann, Adolf. Animal Forms and Patterns: A Study of the Appearance of Animals.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.