1. http://www.ecpa.be/en/pesticides/
2. http://ec.europa.eu/environment/ppps/pdf/ statistics_regulation.pdf
3. http://en.wikipedia.org/wiki/Fungicide
4. http://www.frac.info/frac/publication/anhang/ FRAC_CODE_LIST.pdf
5. http://en.wikipedia.org/wiki/Herbicides