For the breakdown of these regions into mountain groups see the [[List of mountain groups in the Alpine Club classification of the Eastern Alps]]. The [[Swiss Alpine Club]] (SAC) has a slightly different classification of the ranges, based on the political borders in the canton of Graubünden. In Italy the 1926 [[Partizione delle Alpi]] concept is quite common, recently superseded by the [[SOIUSA]] attempt to combine the different approaches. Other specific, especially [[Hydrography|hydrographical]] arrangements are also in use.