Machinery 136 Electric machinery 107 Refrigeration and refrigerating machinery 92 Agricultural machinery 87 Congresses 66 Pumping machinery 63 Hydraulic machinery 62 History 49 Air conditioning 44 Machinery in the workplace 42 Design and construction 37 Machinery industry 36 Machinery, Kinematics of 36 Maintenance and repair 32 Periodicals 30 Bearings (Machinery) 27 Heating 26 Mechanical engineering 26 Testing 25 Equipment and supplies 24 Vibration 20 Handbooks, manuals, etc 19 Alternating current 18 Oil hydraulic machinery 18 Fans (Machinery) 17 Standards 16 Textile machinery 15 Earthmoving machinery 14 Mechanical movements 14 Mining machinery 14