References.

These are my references:

http://www.premierleague.com/page/Home/0,,12306,00.html 

http://www.manutd.com/en/Players-And-Staff/Managers/Alex-Ferguson.aspx 

http://www.chelseafc.com/page/TeamHistory/0,,10268,00.html

http://www.chelseafc.com/page/Past_Managers_Details/0,,10268~1877681,00.html

http://www.arsenal.com/history

http://en.wikipedia.org/wiki/Alex_Ferguson

http://en.wikipedia.org/wiki/Ars%C3%A8ne_Wenger

http://en.wikipedia.org/wiki/Jos%C3%A9_Mourinho

http://en.wikipedia.org/wiki/The_premier_league

http://www.siralexferguson.net/