Gaya APA

Merk, O., Dang, T, T. (2012). Efficiency of world ports in container and bulk cargo (oil, coal, ores and grain) . France: OECD.

Gaya MLA

Merk, Olaf., Dang, Thai, Thanh. "Efficiency of world ports in container and bulk cargo (oil, coal, ores and grain)". France: OECD, 2012. Article.