1. David Falk, Dieter Brill, and David Stork, Seeing the Light: Optics in Nature, Photography, Color, Vision, and Holography (Wiley and Sons Inc., Chichester, 1986), p. 360.
2. The broken-protractor prediction trick
3. Some Activities with Polarized Light from a Laptop LCD Screen
4. “How To Create Color Wheel Diagram In PowerPoint,” YouTube, https://www.youtube.com/watch?v=d_MNUVYhfuQ.