These are also available on Stephen Welch's youtube channel[1]. He uploaded the last one in this series Janaury 2015.
[1]: https://www.youtube.com/playlist?list=PLiaHhY2iBX9hdHaRr6b7X...
[1]: https://www.youtube.com/playlist?list=PLiaHhY2iBX9hdHaRr6b7X...
Please submit the original source. If a post reports on
something found on another site, submit the latter.
The youtube URL you cited would probably be a better source link.