Labor unions History 195 Working class 101 Industrial relations 84 Political activity 52 Collective bargaining 31 Labor movement 26 Labor laws and legislation 21 Law and legislation 21 Employees 20 Officials and employees 20 Wages 19 Economic conditions 18 Politics and government 17 Strikes and lockouts 17 Labor policy 16 Congresses 15 Biography 12 Labor economics 12 Coal miners 11 Socialism 11 Case studies 10 Economic policy 10 Elections 10 Employee participation 10 Management 10 Social conditions 10 Trade-unions 10 Employers' associations 8 Labor disputes 8