Authors:

The main factors in terms of how tiring a season can be are governed by the number of races and the length of time between the first and the last.

"Formula One teams must come together over Bahrain issue" by Allan McNish, www.theguardian.com. June 4, 2011.
The main factors in terms of how tiring a season can be are governed by the number of races and the length of time between the first and the last.