8Vroom, Victor H: Work and Motivation, New York:John Wiley & Sons, 1964.
9Schultzo, C (1969) , "The Role of Incentives, Penalties, and Rewards in Attaining Effective Policy", In The Analysis and Evaluationl of Public Expenditures: The PPB System, Vol. 1, Joint Economio Committee Compendium, 91^st Congress, 1st Session.
