APA

Lundh J. P., . (1966). Notes on Opuntia at Puerto Villamil, Galápagos Islands. : .

Chicago

Lundh J P, . 1966. Notes on Opuntia at Puerto Villamil, Galápagos Islands. : .

Harvard

Lundh J. P., . (1966). Notes on Opuntia at Puerto Villamil, Galápagos Islands. : .

MLA

Lundh J P, . Notes on Opuntia at Puerto Villamil, Galápagos Islands. : . 1966.