APA

Deak A., Ulrich I., Jakob K., Hungarian Oil and Gas Company, World Petroleum Congress (15th. : 1997 : Beijing), Ulrich I., Jakob K. & Hungarian Oil and Gas Company.Downstream challenges-developing market economy in central-eastern Europe. : .

Chicago

Deak Arpad, Ulrich Istvan, Jakob Karoly, Hungarian Oil and Gas Company, World Petroleum Congress (15th. : 1997 : Beijing), Ulrich Istvan, Jakob Karoly and Hungarian Oil and Gas Company.Downstream challenges-developing market economy in central-eastern Europe. : .

Harvard

Deak A., Ulrich I., Jakob K., Hungarian Oil and Gas Company, World Petroleum Congress (15th. : 1997 : Beijing), Ulrich I., Jakob K. and Hungarian Oil and Gas Company.Downstream challenges-developing market economy in central-eastern Europe. : .

MLA

Deak Arpad, Ulrich Istvan, Jakob Karoly, Hungarian Oil and Gas Company, World Petroleum Congress (15th. : 1997 : Beijing), Ulrich Istvan, Jakob Karoly and Hungarian Oil and Gas Company.: . .