Also, see this TurboTax article on Form 4136: Credit for Federal Tax Paid on Fuels - https://turbotax.intuit.com/tax-tips/small-business-taxes/what-is-form-4136-credit-for-federal-tax-p...
IRS Form 4136 and Instructions - https://www.irs.gov/forms-pubs/about-form-4136
