Crawford, R. (1991). In the era of human capital: The emergence of talent, intelligence, and knowledge as the worldwide economic force and what it means to managers and investors. New York: HarperBusiness.

Crawford, Richard. In the Era of Human Capital: The Emergence of Talent, Intelligence, and Knowledge As the Worldwide Economic Force and What It Means to Managers and Investors. New York: HarperBusiness, 1991.

Crawford, Richard. In the Era of Human Capital: The Emergence of Talent, Intelligence, and Knowledge As the Worldwide Economic Force and What It Means to Managers and Investors. New York: HarperBusiness, 1991.