Becker, G. S.
(1964). Human capital. Chicago: University of Chicago Press.
2.
Dooley, C. R.
(1945). The training within industry report 1940-1945. Washington, DC: U. S. War Manpower Commission Bureau of Training, Training Within Industry Service.
3.
Nadler, L.
(1970). Developing human resources. Houston, TX: Gulf.
4.
Weinberger, L. A.
(1998). Commonly held theories of human resource development. Human Resource Development International, 1(1), 75-93.
