Beke D., Kismányoky T., Schmidt R., Szakál P. [2006] Yield and soil condition studies in organic fertilisation experiments. Cereal Res. Commun. Vol. 34 no. 1. pp. 119–121
Szakál P. [. , 'Yield and soil condition studies in organic fertilisation experiments ' (2006 ) 34 Cereal Res. Commun. : 119 -121.
Járási É. Zs. [2005] The future prospects of organic farming in Central and Eastern European countries. Annals of PAAE. Vol. VII. Warszawa-Poznan. 2005. No. 6. 43–47
Járási É. Zs. , 'The future prospects of organic farming in Central and Eastern European countries ' (2005 ) VII Annals of PAAE : 43 -47.
Roszik P. [2006] Report on the activity of Biokontroll Hungária Kht. Year 2005. Biokontroll Hungária Kht. Budapest. p. 9
The Australian Organic Industry. A Summary [2004] Commonwealth of Australia. p. 41