Columbia subject headings:
Exclusive licenses--Germany (West)
Petroleum industry and trade--Germany (West)
Restraint of trade--Germany (West)
Service stations--Germany (West)
Harvard subject headings:
Petroleum industry and trade--Germany (West)
Petroleum industry and trade.
Restraint of trade--Germany (West)
Princeton subject headings:
Monopolies--Germany (West)
Petroleum industry and trade--Germany (West)