Jul.22 (GMM/Inautonews.com) A piece of paper helped to calm the situation between warring teammates Lewis Hamilton and Nico Rosberg.

Alone with their dominance in 2014, the pair’s title battle spiralled out of control.

But although they are still fighting head-to-head in a close championship contest again in 2015, the waters have appeared much calmer so far this season.

German Rosberg has now suggested a ‘document’ is the reason for the change.

“There is this document that both of us had to sign,” he is quoted as saying by Roger Benoit, the highly-experienced correspondent for the Swiss newspaper Blick.

Asked about the content of the agreement, Rosberg answered: “About how we have to conduct ourselves on the track. At the start, when overtaking, etc.”

Boss Toto Wolff has also referred to an agreed set of ‘rules of engagement’ to better handle the inter-team battle in 2015.

“We as a team don’t expect them to be nice,” he said. “Or, let’s say, to play friends for the media. What we ask them is to be respectful of each other, to respect the rules of engagement.”

Notwithstanding that, Rosberg says his relationship with Hamilton goes up and down.

“It changes,” he said. “It is a complicated battle because we have to think about the team at the same time as we think about beating each other.

“It is always going to be complicated as both of us want to win, so there’s ups and downs and there is always going to be another down. At the moment, it is ok,” Rosberg added.