Author: Theodore Fitzhugh

This video, https://www.youtube.com/watch?v=KZrQ42mIq1c, can also be seen at https://www.youtube.com/channel/UCRDk7o4DXCCIROXSeL9vrEQ.

This video, https://www.youtube.com/watch?v=rQwDXEPOcJA, can also be seen at https://www.youtube.com/channel/UCnDz5cQzmC_SJ5mGUdhAFfA.

This video, https://www.youtube.com/watch?v=3m1fIMWm1hk, can also be seen at https://www.youtube.com/playlist?list=PLYPSqOd4ItJUeCj1TT5Z21sFw6iz8xumj.