APA

Gray J. E., . (1853). Description of a new species of tortoise (Testudo planiceps), from the Galapagos Islands. : .

Chicago

Gray J E, . 1853. Description of a new species of tortoise (Testudo planiceps), from the Galapagos Islands. : .

Harvard

Gray J. E., . (1853). Description of a new species of tortoise (Testudo planiceps), from the Galapagos Islands. : .

MLA

Gray J E, . Description of a new species of tortoise (Testudo planiceps), from the Galapagos Islands. : . 1853.