What does it Cover?
There should be a mechanism so that the other shareholder/s have first option to acquire the shares at market value.
Without an agreed process there will be a clash of opinion as each shareholder will want a different valuation formula or person valuing the shares according to whether they are selling or buying.
There needs to be pragmatic ‘first steps process’ to try and get the dispute resolved and if that fails a further mechanism as to what form external help would take.