Design and construction 136 Management 51 History 44 Environmental aspects 31 Maintenance and repair 31 Purification 31 Safety measures 30 rhagor ... Standards 30 Materials 29 Water 29 Testing 28 Quality control 27 Computer programs 26 Data processing 25 Digital techniques 25 Production management 25 Equipment and supplies 23 Industrial safety 23 Design 22 Sewage 22 Buildings 21 Computer graphics 21 Electrical engineering 21 Electronic apparatus and appliances 21 Water-supply 21 Computer-aided design 20 Building 19 Integrated circuits 19 Planning 19 Social aspects 19 llai ...