Universities and colleges 65,890
Urbanization 24,110
Underground movements 23,958
Unemployment 21,417
Urban renewal 17,025
Unemployed 12,829
U.S. states 10,353
Utopias 9,570
Unemployment insurance 9,431
Urban policy 9,278
United States 9,201
Usage 9,156
Urban transportation 7,424
Unitarian churches 6,427
Ultra-Orthodox Jews 5,973
Urdu literature 5,810
Uniforms 5,807
Unitarianism 5,730
User interfaces (Computer systems) 5,708
Underground movements, War 5,628
Ulama 5,377
Ukrainians 5,184
Urdu poetry 5,183
Ukrainian language 5,138
Ukrainian literature 4,960
Ukraine 4,282
User Interfaces and Human Computer Interaction 3,974
Urban ecology (Sociology) 3,931
Utilization 3,855
Universalism 3,798
Upper class 3,633
Usury 3,553
Unitarian Universalist churches 3,270
Urban poor 3,195
Underground press publications 3,151
Union catalogs 3,122
Ukiyoe 3,084
Urban economics 3,030
Urdu language 2,791
Universities 2,684
Union lists 2,495
Underwater archaeology 2,393
United Nations 2,320
Unitarians 2,071
Uncles 2,047
Undocumented immigrants 2,029
Uranium 2,020
Underground literature 2,016
Urology 1,979
Uncertainty 1,962
Urban, Rural and Regional Development 1,919
Utopias in literature 1,861
Universités 1,857
Urbanisation 1,857
Ukrainian poetry 1,841
Urinary organs 1,820
Uterus 1,785
User charges 1,771
Urine 1,728
Unity 1,682
Unidentified flying objects 1,666
Urdu fiction 1,626
Uranium ores 1,604
Undercover operations 1,602
Urban beautification 1,550
Urbanisme 1,514
Urban 1,484
Utilitarianism 1,464
Ubiquitous computing 1,453
Ultrasonic imaging 1,421
Ukrainian 1,420
Urban geography 1,382
Urban transportation policy 1,329
Unmarried mothers 1,326
Upper atmosphere 1,323
Unitarian Universalists 1,320
Ultrasonography 1,317
Urologic Diseases 1,316
Ukraine Conflict, 2014- 1,315
Unemployment rate 1,302
Urban landscape architecture 1,296
Universalist churches 1,253
Unified operations (Military science) 1,235
Unmarried couples 1,209
University extension 1,200
Usury laws 1,151
Ultraviolet radiation 1,119
Uighur (Turkic people) 1,114
Urdu 1,083
Underground Railroad 1,057
Uranium mines and mining 1,041
Urban runoff 1,041
Universalists 1,029
Urban ecology (Biology) 990
UE/CE Etats membres 988
Undocumented Immigrants 987
Umbanda (Cult) 981
Urban health 955
Urban youth 947
Ukrainian fiction 945