"Duty-free importation United States." . . "United States." . . "United States." . . "Energy conservation Law and legislation." . . . . . . . . . "Energy tax act of 1978 : [an act to provide tax incentives for the production and conservation of energy, and for other purposes]"@en . . . "Energy tax act of 1978 : [an act to provide tax incentives for the production and conservation of energy, and for other purposes]" . . . . . . . . . . . . "Energy tax." . . "Energy conservation Law and legislation United States." . . . . "Duty-free importation." . . "Energy tax United States." . .