Columbia subject headings:
Clemens, Olivia Langdon, 1845-1904.
Twain, Mark, 1835-1910.
Harvard subject headings:
Authors, American--19th century--Correspondence
Authors, American--20th century--Correspondence
Clemens, Olivia Langdon, 1845-1904--Correspondence.
Love-letters.
Twain, Mark, 1835-1910--Correspondence.
Princeton subject headings:
Authors, American--19th century--Correspondence.
Clemens, Olivia Langdon, 1845-1904--Correspondence.
Fiction.
Love-letters.
Twain, Mark, 1835-1910. Correspondence.