APA

Estados Unidos. Energy Information Administration, .Derivatives and risk management in the petroleum, natural gas, and electricity industries. : .

Chicago

Estados Unidos. Energy Information Administration, .Derivatives and risk management in the petroleum, natural gas, and electricity industries. : .

Harvard

Estados Unidos. Energy Information Administration, .Derivatives and risk management in the petroleum, natural gas, and electricity industries. : .

MLA

Estados Unidos. Energy Information Administration, .: . .