Interlocking Directorates -- See Also Cartels Here are entered works on combinations in restraint of trade in which independent business enterprises formally agree among themselves to control or limit output, prices, and/or markets so as to achieve monopolistic power. Works on combinations in which stock ownership is transferred to trustees, who in turn issue trust certificates and dividends and who attempt to achieve monopolistic control over output, prices, or markets, are entered under Trusts, Industrial.