https://en.wikipedia.org/wiki/TaX_Foundation... About TAXES...

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The Tax Foundation has received funding from ExxonMobil[40] and from conservative political groups such as the Koch Family Foundations,[41] the Earhart Foundation,[42] and numerous others.[43]

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See also:

Americans For Fair Taxation
Americans for Tax Reform
Brookings Institution
Cato Institute
Center on Budget and Policy Priorities
Citizens for Tax Justice
Heritage Foundation
Koch Family Foundations
National Taxpayers Union
Tax Policy Center
Urban Institute

in: https://en.wikipedia.org/wiki/Tax_Foundation