This document contains 3 YouTube video links without any additional context. The videos are unrelated and there is no clear main topic or essential information to summarize from just the links alone.

1. http://www.youtube.com/watch?v=xVbgxTabuLs
https://www.youtube.com/watch
?v=ilkOhxYpb4o

15. http://www.youtube.com/watch?v=IX2pxtkhx-M