References
- Boren, H. E. (1967). A Computer Program for Determining Aircraft Development and Production Costs. Santa Monica, CA: RAND Corporation.
- The Donald C. & Elizabeth M. Dickinson Research Center. (2005, September). Retrieved from https://www.nationalcowboymuseum.org/research/about/drchistory.aspx
- Doughty, G. W. (1998). The homestead laws: Ponca City, OK. North Central Oklahoma Historical Association. Retrieved from http://homesteadcongress.blogspot.com/2009/02/oklahoma-land-rush.html
- Forecast International. (2001). Business Aircraft Forecast 2002 through 2011. Newton, CT: Forecast International.
- National Drought Mitigation Center. (2006). Drought in the Dust Bowl Years. Retrieved from http://en.wikipedia.org/wiki/Dust_Bowl
- Raymer, D. P. (1989). Aircraft Design: A Conceptual Approach (1st Edition: 1989; 3rd Edition: 1999). Reston, VA: American Institute of Aeronautics and Astronautics.