Oskam, A. J. (1988). The Superlevy, is there an alternative?: Final report of an investigation into the functioning of the superlevy in the European Community and the consequences of a number of policy alternatives for the period 1989-1997. Wissenschaftsverlag Vauk.

Oskam, A. J. The Superlevy, Is There an Alternative?: Final Report of an Investigation into the Functioning of the Superlevy in the European Community and the Consequences of a Number of Policy Alternatives for the Period 1989-1997. Kiel: Wissenschaftsverlag Vauk, 1988.

Oskam, A. J. The Superlevy, Is There an Alternative?: Final Report of an Investigation into the Functioning of the Superlevy in the European Community and the Consequences of a Number of Policy Alternatives for the Period 1989-1997. Wissenschaftsverlag Vauk, 1988.