Παραπομπή APA

Institute of Shipping Economics. (1981). Shipping statistics yearbook 1981: Facts and figures about shipping, shipbuilding, seaports and sea-borne trade. Bremen: Institute of Shipping Economics.

Παραπομπή Chicago Style

Institute of Shipping Economics. Shipping Statistics Yearbook 1981: Facts and Figures About Shipping, Shipbuilding, Seaports and Sea-borne Trade. Bremen: Institute of Shipping Economics, 1981.

Παραπομπή MLA

Institute of Shipping Economics. Shipping Statistics Yearbook 1981: Facts and Figures About Shipping, Shipbuilding, Seaports and Sea-borne Trade. Bremen: Institute of Shipping Economics, 1981.

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