The Bitzuma company was founded by a group belonging to the prestigious Princeton University, this company sells software and books, they have books related to blockchain technologies, I imagine that to promote the books they posted a number of videos on the YouTube platform. You can enter the courses and their content from its simple website, where the topics and their content are specified. There are a total of 60 short videos. The topics are about bitcoin and the Blockchain platform. They are quite basic and since their publication there have been important advances in this technology and their content has not been added or updated. From the web if you wish you can buy the books