Perry, J. L. (1996). Measuring public service motivation: An assessment of construct reliability and validity. Journal of Public Administration Research and Theory, 6, 5-22.
 Perry, J. L. (2000). Bringing society in: Toward a theory of publicservice motivation. Journal of Public Administration Research and Theory, 10, 471-488.
 Rainey, H. G. (1982). Reward preferences among public and private managers: In search of the service ethic. American Review of Public Administration, 16, 288-302.
 Wittmer, D. (1991). Serving the people or serving for pay: Reward preferences among government, hybrid sector, and business managers. Public Productivity & Management Review, 14, 369-383.