Book review: The Principle of Subsidiarity and its Enforcement in the EU Legal Order. The Role of National Parliaments in the Early Warning System, by Katarzyna Granat. (Oxford: Hart Publishing - Common Market Law Review View Book review: The Principle of Subsidiarity and its Enforcement in the EU Legal Order. The Role of National Parliaments in the Early Warning System, by Katarzyna Granat. (Oxford: Hart Publishing by - Common Market Law Review Book review: The Principle of Subsidiarity and its Enforcement in the EU Legal Order. The Role of National Parliaments in the Early Warning System, by Katarzyna Granat. (Oxford: Hart Publishing 56 3 Common Market Law Review