Art (Modern)--Economic aspects--England--London--21st century Art (Modern)--Economic aspects--European Union countries--21st century Art museums--England--London--21st century--Exhibitions Bill Viola (1951-)--Career in art Customs administration--England--London--21st century Customs administration--European Union countries--21st century Dan Flavin (1933-1996)--Career in art Duty-free importation--England--London--21st century Duty-free importation--European Union countries--21st century Fluorescent-light sculpture--England--London--21st century Haunch of Venison (Gallery)--21st century--Exhibitions Tariff on art--England--London--21st century Tariff on art--European Union countries--21st century Video installations (Art)--England--London--21st century