Međunarodnog udruženja proizvođača umjetnog gnojiva https://www.fertilizer.org/images/Library_Downloads/2017_IFA_Annual_Conference_Marrakech_PIT_AG_Fertilizer_Outlook.pdf ili „Priručnik grupacije Yara o industriji gnojiva, siječanj 2017.” https://www.yara.com/siteassets/investors/057-reports-and-presentations/other/2017/fertilizer-industry-handbook_2017_slides_only.pdf/ .
Fertilizers Europes presentationsmaterial från hörandet den 12 april 2018 och bilagan ”Roadmap for the development of production of mineral fertilizers for the period until 2025”.