The following list does not attempt to represent the periodical material except for one symposium in The Bookman. See the Reader’s Guide to Periodical Literature. The volume for 1910–1914 alone contains seventy-six items.
Clemens, W. M. Mark Twain: his Life and Work. 1892.
Henderson, Archibald. Mark Twain. 1912.
Howells, W. D. My Mark Twain. 1910.
Mark Twain’s Letters (edited by A. B. Paine). 1917.
Matthews, Brander. Inquiries and Opinions. 1907.
Paine, A. B. A Boy’s Life of Mark Twain. 1916.
Pattee, F. L. American Literature since 1870, chap. iii. 1915.
Phelps, W. L. Essays on Modern Novelists. 1910.
Sherman, Stuart. Fifty Years of American Idealism (edited by Gustav Pollak). 1915. Also in On Contemporary Literature. 1918.