Neb. Rev. Stat. § 57-511: Neb. Rev. Stat. § 57-511

An invoice shall be submitted to the purchaser showing the quantity of liquefied petroleum gas sold, expressed in pounds, or gallons, or cubic feet, or other unit approved by the Department of Agriculture. When vapor meters reading in approved units other than cubic feet are used, the invoice shall clearly indicate to the purchaser a factor to convert to gallons.