Sir Alex Ferguson's new book 'Leading' -- the highlights from the United legend

Former Manchester United manager Sir Alex Ferguson's new book, "Leading," is to be published on Tuesday, and here ESPN FC highlights the key points revealed by the Scot who won an incredible 13 Premier League titles at Old Trafford.

"It was simple. We just agreed that no player should be paid more than me."

Ferguson signed a contract with Manchester United in 2010 that ensured he would receive a higher salary than any of his players, an agreement made as Wayne Rooney was about to get a big pay rise by signing a new deal following protracted negotiations. Read more.

"There are one or two football agents I simply do not like. And Mino Raiola, Paul Pogba's agent, is one of them."

Ferguson has blamed Paul Pogba's agent for the midfielder's departure from United. Pogba, 22, joined Juventus when his contract at Old Trafford expired in 2012 but Ferguson claimed Pogba was willing to sign an extended deal until Mino Raiola became his representative and intervened. Read more.

"Are there players who have played right through the whole of the Premier League and performed at the level they [Ryan Giggs and Paul Scholes] have? There are none, absolutely none."

Ferguson says he worked with just four world-class players at United -- and Wayne Rooney, Roy Keane and David Beckham were not among them. The Scot nominated Eric Cantona, Cristiano Ronaldo, Ryan Giggs and Paul Scholes as the quartet who were at the very highest level. Read more.

"I had dinner with Pep Guardiola in New York in 2012, but couldn't make him any direct proposal because retirement was not on my agenda at that point."

Ferguson first approached Pep Guardiola about succeeding him as United manager before finally settling on David Moyes. Ferguson says he met with Guardiola before his final season as United boss began in 2012. Read more.

"His [Sergio Aguero's] agent was demanding a price we were not prepared to pay."

Ferguson considered signing Sergio Aguero for United in 2011 but backed out because the player's agent's demands were too high. Instead, Aguero joined Manchester City for £38 million and scored the goal that cost United the Premier League title the following season. Read more.

And finally, the letter Ferguson wrote to the recently-retired Eric Cantona back in 1997.