In Barr v. Petzhold, 77 Ariz. 399, 273 P.2d 161 (1954) the Arizona Supreme Court affirmed a trial court's determination that certain property could not be reached by a husband's separate creditor. Id. at 409-10, 273 P.2d at 167. In so ruling, our high court observed that when doubt exists about whether income is the result of a spouse's skill, labor, or management during the marriage, as opposed to an inherent return on a separate investment, such doubt is generally resolved by finding the income the product of community effort, because there is a "strong presumption . . . that all earnings during coverture are community in nature." Id. at 409, 273 P.2d at 167.