APA
Transport Commission of the European Communities, . (1991). Europa transport. Observations of transport markets. Annual report 1989. Bryssel: Transport Commission of the European Communities.
Chicago
Transport Commission of the European Communities, . 1991. Europa transport. Observations of transport markets. Annual report 1989. Bryssel: Transport Commission of the European Communities.
Harvard
Transport Commission of the European Communities, . (1991). Europa transport. Observations of transport markets. Annual report 1989. Bryssel: Transport Commission of the European Communities.
MLA
Transport Commission of the European Communities, . Europa transport. Observations of transport markets. Annual report 1989. Bryssel: Transport Commission of the European Communities. 1991.