Due to a shortage of train crew Cross Country are to run a reduced timetable for this 3 month period.
Two of the headline changes are no XC trains beyond Edinburgh to Glasgow and Aberdeen, also reducing the Reading to Oxford to Birmingham service to hourly, from half hourly.
The ones which start and terminate at Reading are the ones which are cancelled.
Anyone with existing bookings should check carefully for changes, compounded by the fact that the revised timetables are only being announced on a rolling weekly basis, at least to start with.