↑ "The two parts of The Pilgrim's Progress in reality constitute a whole, and the whole is, without doubt, the most influential religious book ever written in the English language" (Alexander M. Witherspoon in his introduction, John Bunyan, The Pilgrim's Progress (New York: Pocket Books, 1957), vi.
↑ John Bunyan, The Pilgrim's Progress, W.R. Owens, ed., Oxford World's Classics (Oxford: Oxford University Press, 2003), xiii.
↑ Abby Sage Richardson, Familiar Talks on English Literature: A Manual (Chicago, A.C. McClurg & Co., 1892), 221.
↑ "For two hundred years or more no other English book was so generally known and read" (James Baldwin in his foreword, James Baldwin, John Bunyan's Dream Story (New York: American Book Co., 1913), 6).
