APA

Grant P. R. B. P. T. S. D., . (1979). A bill color polymorphism in young Darwin's finches. : .

Chicago

Grant P R Boag P T Schluter D, . 1979. A bill color polymorphism in young Darwin's finches. : .

Harvard

Grant P. R. B. P. T. S. D., . (1979). A bill color polymorphism in young Darwin's finches. : .

MLA

Grant P R Boag P T Schluter D, . A bill color polymorphism in young Darwin's finches. : . 1979.