...documents under the provisions of this section. (g) Any of the district courts of the United States within the jurisdiction of which such inquiry is carried on may, in case of contumacy or refusal to obey a subpena issued to any common carrier or licensee or other person, issue an order requiring such...

...witnesses and the production of documentary evidence. Any of the district courts of the United States within the jurisdiction of which such inquiry is carried on may, in case of contumacy or refusal to obey a subpoena issued to any person, partnership, or corporation issue an order requiring such person,...

...subpoena; court order; contempt Any court of the United States within the jurisdiction of which an Inquiry is carried on may, In case of contumacy or refusal to obey a subpoena for any reason, iasue an order requiring such person to appear before the Commission...