Jol (Yule): The Norse Winter Holiday:

 https://www.youtube.com/watch?v=UUloIBXFOQE

Viking Yule – What was it?:

 https://www.youtube.com/watch?v=OixIUmEIdks

Christmas Origins with Survive the Jive:

 https://www.youtube.com/watch?v=5z0cLSpx5Mk

Jol Date Study:

 https://www.academia.edu/1366945/Jul_disting_och_f%C3%B6rkyrklig_tider%C3%A4kning

Bonus Source on Saturnalia:

 https://www.youtube.com/watch?v=5lsctaPJSvo