Question: Lincoln the Unknown is a biography of Abraham Lincoln, written in what year, by Dale Harbison Carnegie, was an American writer and lecturer and the developer of famous courses in self-improvement, salesmanship, corporate training, public speaking, and interpersonal skills?
Sentence (from "Public Speaking and Influencing Men in Business"): A more recent revised edition is "Public Speaking for Success" (2005), revised by Arthur Pell, which restores content that was left out of the Dorothy Carnegie-revised works.
Relevant evidence: No