research on animation

http://www.youtube-nocookie.com/watch?v=bXVyXFAbkfU
http://www.youtube-nocookie.com/watch?v=ZZFXi8SF5EU
http://www.youtube-nocookie.com/watch?v=L-PyTd0Oo5U&feature=related
http://www.youtube-nocookie.com/watch?v=qmGVYki-oyQ&p=7E912FF5A1F7ACDF&playnext=1&index=41