What is the test for abuse of a district court's decision not to order a presentence study?

We review for abuse of discretion a district court's decision whether to order a presentence study under 18 U.S.C. Sec. 3552(b). See 18 U.S.C. Sec. 3553(b); see also United States v. Robinson, 967 F.2d 287, 291 (9th Cir.1992) (district court's denial of motion for a continuance of trial is reviewed for abuse of discretion). We review findings of fact underlying a sentencing determination for clear error. United States v. Upshaw, 918 F.2d 789, 791 (9th Cir.1990), cert. denied, 111 S.Ct. 1335 (1991).