Columbia subject headings:
Harvard subject headings:
Authors, American--19th century--Biography
Humorists, American--19th century--Biography.
Twain, Mark, 1835-1910
Twain, Mark, 1835-1910--Biography.
Princeton subject headings:
Authors, American--19th century--Biography.
Humorists, American--19th century--Biography.
Twain, Mark, 1835-1910.