_Thoreau_, _his Life and Aims_, by H. A. Page (Chatto & Windus).
_Thoreau_, by H. S. Salt ("Great Writers Series"). Essays by R. L.
Stevenson (_Familiar Studies of Men and Books_), and J. R. Lowell (_My
Study Window_).
The best edition of Thoreau's writings is published by the Riverside
Press, Cambridge, U.S.A. Some useful volumes of selections are issued by
Walter Scott, Limited, with good introductions by Will. H. Dricks.
_Walden_, with introduction by Theodore Watts-Dunton (Henry Froude).