Gaya APA

Babri, S. et al (2015). Application of gravity models with a fixed component in the international trade flows of coal, iron ore and crude oil . Germany: Taylor and Francis.

Gaya MLA

Babri, Sahar. et al. "Application of gravity models with a fixed component in the international trade flows of coal, iron ore and crude oil". Germany: Taylor and Francis, 2015. Article.