1. 2016. Elements of Art. http://www.getty.edu/education/teachers/building_lessons/formal_analysis.html. (2016). http://www.getty.edu/education/teachers/building_lessons/formal_analysis.html (accessed September 12, 2016).
2. 2017. OpenCycleMap. https://www.opencyclemap.org/. (2017). https://www.opencyclemap.org/ (accessed January 2, 2017).
3. Tomas Akenine-Möller, Eric Haines, and Naty Hoffman. 2008.Real-Time Rendering 3rd Edition.A. K. Peters, Ltd., Natick, MA, USA. 1045 pages.
4. Margarita Bratkova, Peter Shirley, and William B. Thompson. 2009. Artistic Rendering of Mountainous Terrain.ACM Trans. Graph.28, 4, Article 102 (Sept. 2009), 17 pages.
5. J. Brosz and F. Samavati. 2010. Shape Defined Panoramas. InShape Modeling International Conference (SMI), 2010.IEEE Computer Society, 57--67.