OPINION

Donnie Lee Dixon, Leroy Cornelius Watkins, and Antoine Lavar Dixon appeal from their convictions and sentences, imposed pursuant to guilty pleas, for distribution of cocaine and cocaine base and conspiracy to possess with intent to distribute and to distribute cocaine and cocaine base, in violation of 21 U.S.C. §§ 841(a)(1), 846 (2000). Finding no error, we affirm.

Appellants contend the district court did not make adequate findings of fact as required by Fed.R.Civ.P. 32 after they objected to the findings in their presentence reports. Because Appellants did not raise this argument at sentencing, review is for plain error. See United States v. Olano, 507 U.S. 725, 732, 113 S.Ct. 1770, 123 L.Ed.2d 508 (1993). We find no error, plain or otherwise.

Appellants next contend the district court incorrectly calculated the amount of *923 drugs for which they should each be held responsible because government witness James Davis was not credible. This court reviews a district court’s factual findings for clear error and its application of the Sentencing Guidelines de novo. United States v. Daughtrey, 874 F.2d 213, 217 (4th Cir. 1989). In conducting this review, the district court’s application of the Sentencing Guidelines are given due regard to the opportunity of the district court to judge the credibility of witnesses. 18 U.S.C. § 3742(e) (1994). Credibility determinations will therefore receive deference unless they are without support in the record. United States v. Brown, 944 F.2d 1377, 1379-80 (7th Cir. 1991). Given the district court’s unique ability to make credibility determinations, we find no clear error.

Donnie Dixon and Leroy Watkins have filed motions for permission to file pro se supplemental briefs in this court. While we grant their motions, we find no merit in the allegations raised in their pro se briefs.

Accordingly, we affirm Appellants’ convictions and sentences. We dispense with oral argument because the facts and legal contentions are adequately presented in the materials before the court and argument would not aid the decisional process.

AFFIRMED.