Attorney General filed series of cases under state and federal antitrust statutes against oil companies alleging horizontal price-fixing and other agreements. Defendants in some of these litigations filed separate action for declaratory judgment contending that Attorney General did not have standing to bring parens patriae action under 15 U.S.C. § 15c. On Attorney General’s appeal from declaratory judgment, Missouri Supreme Court held that Attorney General may institute proceedings in parens patriae capacity to vindicate the rights of all Missouri citizens pursuant to the authority conferred upon the Attorney General by Mo. Rev. Stat. §§ 27.060, 416.061.