This video gives a basic rundown of the Spanish Civil War

https://study.com/academy/lesson/the-spanish-civil-war-the-influence-of-foreign-powers.html

History of the Polikarpov and soviet covert involvement in the Spanish Civil war with its associated extension in Stalin's purges.

https://www.youtube.com/watch?v=cWDbUQx6DPg

This video is of the end of the Spanish Civil War with footage from the time.

https://www.youtube.com/watch?v=AIjIbJU0Tb0

This video is of a simulation of aerial combat during the war.

https://www.youtube.com/watch?v=E_l1zVk6pYg

 This video explains life stories from Spanish refugees from the end of the Spanish civil war and the crackdown afterward.

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

This video explains about how franco clamped down dissent especially in the case of Jehovah's witnesses for their conscientious objection to serving in the military.

https://tv.jw.org/#en/mediaitems/docid-502018517_1_VIDEO