1. Betty Edwards. 1979. Drawing on the Right Side of the Brain: A Course in Enhancing Creativity and Artistic Confidence. J. P. Tarcher. Betty Edwards. 1979. Drawing on the Right Side of the Brain: A Course in Enhancing Creativity and Artistic Confidence. J. P. Tarcher.
2. Yulia Gryaditskaya , Felix Hähnlein , Chenxi Liu , Alla Sheffer , and Adrien Bousseau . 2020. Lifting freehand concept sketches into 3D. TOG 39, 6 ( 2020 ), Article 167, 16 pages. Yulia Gryaditskaya, Felix Hähnlein, Chenxi Liu, Alla Sheffer, and Adrien Bousseau. 2020. Lifting freehand concept sketches into 3D. TOG 39, 6 (2020), Article 167, 16 pages.
3. OpenSketch
4. How2Sketch
5. Conquering the cube