1. Feedstocks for the chemical industry , dena (German Energy Agency) , 2019 , https://www.dena.de/fileadmin/dena/Publikationen/PDFs/2019/Feedstocks_for_the_chemical_industry.pdf
2. Food and Agriculture Organization , 2019 , https://knoema.com/FAORFBFP/faostat-fertilizers-by-product .
3. A. Bazzanella and D.Krämer , Technologies for sustainability and climate protection – chemical processes and use of co2 , DECHEMA , 2019
4. The Chemistry of CO: Carbonylation
5. J. Hagen , Industrial catalysis: A practical approach , John Wiley & Sons , 2015