Department of the Treasury, Internal Revenue Service (IRS), Internal Revenue Service (IRS)

• National Taxpayer Advocate Purple Book
• Guía Tributaria de para Personas Físicas, Publicación 17, el Impuesto Federal Sobre Los Ingresos
• Publication 3 Armed Forces' Tax Guide
• Tax Guide 2018, Publication 17, Your Federal Income Tax for Individuals
• Tax Guide 2019, Publication 17, Your Federal Income Tax for Individuals
• Tax Guide for Individuals, Publication 17, Your Federal Income Tax for Individuals
• Tax Guide for Small Business, Publication 334, for Individuals Who Use Schedule C