Quirk, T. (2007). Mark Twain and human nature. University of Missouri Press.
Lua i Stíl Chicago (17ú heag.)Quirk, Tom. Mark Twain and Human Nature. Columbia: University of Missouri Press, 2007.
Lua MLA (9ú heag.)Quirk, Tom. Mark Twain and Human Nature. University of Missouri Press, 2007.
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