Article 9

(a) prescribed classes of employees, constituting not less than 50 per cent, of all employees, and also their wives and children; or

(b) prescribed classes of the economically active population, constituting not less than 20 per cent, of all residents, and also their wives and children; or

(c) prescribed classes of residents, constituting not less than 50 per cent, of all residents; or

(d)where a declaration made in virtue of Article 3 is in force, prescribed classes of employees constituting not less than 50 per cent, of all employees in industrial workplaces employing 20 persons or more, and also their wives and children.