Former Manchester United boss Sir Alex Ferguson has collaborated with a Harvard Business School professor to analyse his successful management style, reports BBC Sport. The Harvard Business Review has published the findings in its October edition under the headline "Ferguson's Formula".

The study includes Sir Alex's own account of his strategy during 26 seasons in charge of the Red Devils.

"Before I came to United, I told myself I wasn't going to allow anyone to be stronger than I was. Your personality has to be bigger than theirs. That is vital," he advises.