1. Conner, M. (2015, July). Motivation in second language education.
2. Davis, Beverly M. (2004). The impact of leadership on employee motivation.
3. Dixon, P. (2015, July). Motivation - The reason for the crisis.
4. Hiam, A. (2003). Motivational management: Inspiring your people for maximum performance.
5. Kuczmaraski, S. and Kuczmarski, T. (1995). Values-based leadership rebuilding employee commitment, performance and productivity. Englewood Cliffs, NJ: Prentice Hall, Inc.