Universities and colleges 149 United States 68 Usage 26 Universities 22 Utopias 21 Underground movements 20 Upper class 20 Urban 19 Underground Railroad 18 Unidentified flying objects 17 Urbanization 17 Underground railroad 16 Unemployment 12 Urban renewal 12 Utilization 12 Undercover operations 11 Unemployed 10 Urban policy 10 Underwater archaeology 9 Unmarried mothers 8 U.S. states 7 Uncles 7 Underwater exploration 7 Urban ecology (Sociology) 7 Urban poor 7 Uniforms 6 Universités 6 Undertakers and undertaking 5 Upper class families 5 Urban & Land Use Planning 5 Urban health 5 Urban youth 5 User interfaces (Computer systems) 5 University extension 4 Unskilled labor 4 Urban beautification 4 Urban economics 4 Urban transportation 4 USA 3 Ugliness 3 Umweltpolitik 3 Umweltschutz 3 Uncertainty 3 Uncle Tom (Fictitious character) 3 Underground movements, War 3 Unified field theories 3 Union européenne 3 Unionists (United States Civil War) 3 Unmarried couples 3 Unternehmen 3 Unterprivilegierung 3 Upgrading 3 Urban ecology 3 Urban ecology (Biology) 3 Urban geography 3 Urban residence 3 Urban schools 3 Usage des drogues 3 User-generated content 3 Usonian houses 3 Utilitarianism 3 U-2 Incident, 1960 2 UCSD Pascal (Computer program language) 2 UML (Computer science) 2 Ukiyoe 2 Ultrastructure (Biology) 2 Umwelt 2 Umweltschaden 2 Unconscious (Psychology) 2 Underground literature 2 Underwater photography 2 Unilateral acts (International law) 2 United Nations 2 United States in art 2 Universidades 2 University cooperation 2 Unternehmensgründung 2 Unterricht 2 Unterrichtserfolg 2 Upper class women 2 Urban & Regional 2 Urban Health Services 2 Urban Population 2 Urban agriculture 2 Urban animals 2 Urban anthropology 2 Urban folklore 2 Urban landscape architecture 2 Urban transportation policy 2 Urban violence 2 Urban warfare 2 Urbanisme 2 Urine 2 User Generated Content 2 Uxoricide 2 Überlebender 2 U-länder 1 U.S.S.R. Space Programs 1 UCSD Pascal Software System (Computer system) 1 UE/CE Relations extérieures 1