Universities and colleges 65,835
Urbanization 24,083
Underground movements 23,931
Unemployment 20,375
Urban renewal 16,992
Unemployed 12,824
U.S. states 10,364
Utopias 9,556
Unemployment insurance 9,408
Urban policy 9,262
United States 9,211
Usage 9,142
Urban transportation 7,419
Unitarian churches 6,432
Ultra-Orthodox Jews 5,954
Uniforms 5,801
Urdu literature 5,783
Unitarianism 5,740
User interfaces (Computer systems) 5,699
Underground movements, War 5,628
Ulama 5,359
Ukrainians 5,169
Ukrainian language 5,131
Urdu poetry 5,099
Ukrainian literature 4,953
Ukraine 4,290
User Interfaces and Human Computer Interaction 3,968
Urban ecology (Sociology) 3,922
Utilization 3,852
Universalism 3,809
Upper class 3,626
Usury 3,552
Unitarian Universalist churches 3,265
Urban poor 3,185
Underground press publications 3,149
Union catalogs 3,121
Ukiyoe 3,079
Urban economics 3,024
Urdu language 2,789
Universities 2,689
Union lists 2,492
Underwater archaeology 2,387
United Nations 2,341
Unitarians 2,071
Uncles 2,044
Undocumented immigrants 2,036
Uranium 2,015
Underground literature 2,014
Urology 1,979
Uncertainty 1,956
Urban, Rural and Regional Development 1,919
Utopias in literature 1,860
Ukrainian poetry 1,837
Universités 1,823
Urinary organs 1,819
Urbanisation 1,795
Uterus 1,785
User charges 1,770
Urine 1,727
Unity 1,681
Unidentified flying objects 1,662
Uranium ores 1,603
Urdu fiction 1,603
Undercover operations 1,594
Urban beautification 1,549
Urbanisme 1,512
Urban 1,489
Utilitarianism 1,461
Ubiquitous computing 1,448
Ultrasonic imaging 1,421
Ukrainian 1,420
Urban geography 1,383
Urban transportation policy 1,327
Ukraine Conflict, 2014- 1,326
Unmarried mothers 1,324
Upper atmosphere 1,323
Unitarian Universalists 1,318
Urologic Diseases 1,316
Ultrasonography 1,315
Urban landscape architecture 1,295
Universalist churches 1,253
Unified operations (Military science) 1,233
Unmarried couples 1,208
University extension 1,201
Usury laws 1,150
Unemployment rate 1,141
Ultraviolet radiation 1,119
Uighur (Turkic people) 1,109
UE/CE Etats membres 1,103
Urdu 1,083
Underground Railroad 1,056
Uranium mines and mining 1,041
Urban runoff 1,041
Universalists 1,031
Urban ecology (Biology) 989
Undocumented Immigrants 986
Umbanda (Cult) 980
Urban health 951
Unternehmen 949
Urban youth 946