APA

Heller E., Snodgrass R. E., . (1903). Papers from the Hopkins Stanford Galápagos Expedition, 1898-1899. XV. [Washington, D.C.]: Washington Academy of Sciences.

Chicago

Heller Edmund, Snodgrass Robert Evans, . 1903. Papers from the Hopkins Stanford Galápagos Expedition, 1898-1899. XV. [Washington, D.C.]: Washington Academy of Sciences.

Harvard

Heller E., Snodgrass R. E., . (1903). Papers from the Hopkins Stanford Galápagos Expedition, 1898-1899. XV. [Washington, D.C.]: Washington Academy of Sciences.

MLA

Heller Edmund, Snodgrass Robert Evans, . Papers from the Hopkins Stanford Galápagos Expedition, 1898-1899. XV. [Washington, D.C.]: Washington Academy of Sciences. 1903.