Two pools of four teams play three games, one against each other team in their pool.

The twelve participating nations are divided into two pools of six teams.

Both group were arranged in 5 pools of 8 teams.

Six pools of four teams play both home and away games.

The qualification round was completed by two pools of five teams.

The eight teams were divided into two pool of four teams each.

The six teams were divided into two pool of three teams each.

One pool of four teams - winner progresses to round 2.

The 24 pairs were divided into 6 pools of 4 teams.

The championship was decided in a final pool of four teams.