APA

Porter D. M., . (1968). The flora of the Galápagos Islands. : .

Chicago

Porter Duncan M, . 1968. The flora of the Galápagos Islands. : .

Harvard

Porter D. M., . (1968). The flora of the Galápagos Islands. : .

MLA

Porter Duncan M, . The flora of the Galápagos Islands. : . 1968.