title: Three theorems on gradient fields potentially useful in homing pigeon navigation.
authors.affiliation: Dept. Mat. Apl, IME-USP, Brazil. mane@ime.usp.br
authors.forename: M V P
authors.initials: MV
authors.lastname: Garcia
authors.forename: C
authors.initials: C
authors.lastname: Possani
authors.forename: R
authors.initials: R
authors.lastname: Ranvaud
authors.forename: F A
authors.initials: FA
authors.lastname: Tal
mesh_terms: D000818:Animals; D010856:Columbidae / Q000502:physiology*; D005426:Flight, Animal; D008433:Mathematics; D008954:Models, Biological; D012903:Smell