- UDC
Use Classification systems - UFOs
Use Unidentified flying objects - UFOs (unidentified flying objects)
Use Unidentified flying objects - UK economy
Use National economy - UK Parliament
Use Parliament - Ukranian
Use Ukrainian - Ulster Rising (1641)
Use Irish Rebellion (1641) - Uncertainty (emotion)
Use Doubt - Unconcern
Use Apathy - Uncultivated land
Use Wasteland - Underachievers
Use Low achievers - Underground water
Use Groundwater - Underpasses
Use Subways - Underprivileged children
Use Disadvantaged children - Underprivileged groups
Use Disadvantaged groups - Underprivileged youth
Use Disadvantaged youth - Undertakers and undertaking
Use Undertakers and/or Undertaking - Underwater mining
Use Sea bed mining - Underwater oil and gas extraction
Use Sea bed mining - Uneasiness
Use Anxiety - Unemployment and jobseeking
Use Job seeking and/or Unemployment - Unemployment benefits
Use Unemployment benefit - UNIMARC
Use Bibliographic standards - Union catalogues
Use Catalogues - Unitarian churches
Use Churches and/or Unitarianism