Universities and colleges 65,843
Urbanization 24,092
Underground movements 23,941
Unemployment 20,376
Urban renewal 17,003
Unemployed 12,824
U.S. states 10,363
Utopias 9,561
Unemployment insurance 9,409
Urban policy 9,265
United States 9,215
Usage 9,147
Urban transportation 7,421
Unitarian churches 6,426
Ultra-Orthodox Jews 5,956
Urdu literature 5,808
Uniforms 5,802
Unitarianism 5,728
User interfaces (Computer systems) 5,704
Underground movements, War 5,628
Ulama 5,368
Urdu poetry 5,174
Ukrainians 5,172
Ukrainian language 5,134
Ukrainian literature 4,953
Ukraine 4,293
User Interfaces and Human Computer Interaction 3,972
Urban ecology (Sociology) 3,927
Utilization 3,855
Universalism 3,799
Upper class 3,628
Usury 3,553
Unitarian Universalist churches 3,264
Urban poor 3,186
Underground press publications 3,149
Union catalogs 3,122
Ukiyoe 3,080
Urban economics 3,026
Urdu language 2,791
Universities 2,689
Union lists 2,493
Underwater archaeology 2,387
United Nations 2,338
Unitarians 2,070
Uncles 2,047
Undocumented immigrants 2,036
Uranium 2,017
Underground literature 2,015
Urology 1,979
Uncertainty 1,959
Urban, Rural and Regional Development 1,919
Utopias in literature 1,861
Ukrainian poetry 1,837
Universités 1,827
Urinary organs 1,819
Urbanisation 1,803
Uterus 1,785
User charges 1,770
Urine 1,728
Unity 1,682
Unidentified flying objects 1,663
Urdu fiction 1,632
Uranium ores 1,604
Undercover operations 1,596
Urban beautification 1,549
Urbanisme 1,511
Urban 1,490
Utilitarianism 1,462
Ubiquitous computing 1,454
Ultrasonic imaging 1,421
Ukrainian 1,420
Urban geography 1,383
Urban transportation policy 1,327
Ukraine Conflict, 2014- 1,326
Unmarried mothers 1,325
Upper atmosphere 1,323
Unitarian Universalists 1,318
Urologic Diseases 1,316
Ultrasonography 1,315
Urban landscape architecture 1,296
Universalist churches 1,253
Unified operations (Military science) 1,233
Unmarried couples 1,209
University extension 1,201
Usury laws 1,151
Unemployment rate 1,141
Ultraviolet radiation 1,119
Uighur (Turkic people) 1,109
Urdu 1,085
UE/CE Etats membres 1,082
Underground Railroad 1,057
Uranium mines and mining 1,041
Urban runoff 1,041
Universalists 1,029
Urban ecology (Biology) 990
Undocumented Immigrants 986
Umbanda (Cult) 980
Urban health 953
Urban youth 946
Ukrainian fiction 945