Uredbe Vijeća (EZ) br. 1225/2009 (SL L 280, 24.9.2014., str. 19.), uvodna izjava 111.
Se Yara Industry Handbook 2017, https://www.yara.com/siteassets/investors/057-reports-and-presentations/other/2017/fertilizer-industry-handbook_2017_slides_only.pdf/.