APA (7th ed.) Zitazioa

Williston, S. W. Water Reptiles of the Past and Present.

Chicago Style (17th ed.) Zitazioa

Williston, Samuel Wendell. Water Reptiles of the Past and Present.

MLA (9th ed.) Zitazioa

Williston, Samuel Wendell. Water Reptiles of the Past and Present.

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