Não informado. (1950). Quarterly Bulletin of Steel Statistics for Europe. United Nations, Economic Commission for Europe.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Quarterly Bulletin of Steel Statistics for Europe. Geneve, Suíça: United Nations, Economic Commission for Europe, 1950.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Quarterly Bulletin of Steel Statistics for Europe. United Nations, Economic Commission for Europe, 1950.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.