History 204 Education 104 Histoire 95 Design and construction 52 Geology 48 Teachers 48 Coal mines and mining 47 more ... Politics and government 47 Attitudes 39 Géologie 34 Geology, Stratigraphic 32 Stratigraphie 31 Charbon 28 Social conditions 28 Training of 27 African Americans 26 Collective bargaining 26 Economic conditions 25 Éducation 24 Economic history 23 Study and teaching 23 Employment 20 Music 20 Politique et gouvernement 20 Public schools 20 Environmental aspects 19 Finance 19 Frères moraves 19 Dissertations, Academic 18 Enseignants 18 less ...