Stansberry, P. (2015). America 2020: The survival blueprint. Stansberry Research.
Cita Chicago (17th ed.)Stansberry, Porter. America 2020: The Survival Blueprint. USA: Stansberry Research, 2015.
Cita MLA (9th ed.)Stansberry, Porter. America 2020: The Survival Blueprint. Stansberry Research, 2015.
Atenció: Aquestes cites poden no estar 100% correctes.