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U.S. Code Title 26
Subtitle F
Chapter 67
Subchapter A
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Subchapter A: Interest on Underpayments
Section 6601: Interest on underpayment, nonpayment, or extensions of time for payment, of tax
Section 6602: Interest on erroneous refund recoverable by suit
Section 6603: Deposits made to suspend running of interest on potential underpayments, etc.