1. Armengot L, José-María L, Chamorro L, Sans FX (2013) Weed harrowing in organically grown cereals crops avoids yield losses without reducing weed diversity. Agron Sustain Dev 33:405–411. doi: 10.1007/s13593-012-0107-8
2. Bates D, Maechler M, Dai B (2008) lme4: linear mixed-effects models using S4 classes. Version 0.999375-27. http://lme4.r-forge.r-project.org/ . Accessed 19 Feb 2009
3. Baayen RH (2008) languageR: data sets and functions with “analyzing linguistic data: a practical introduction to statistics”. R package version 0.953. Accessed 19 Feb 2009
4. Basch G, González-Sánchez EJ, Gómez McPherson H, Kassam A (2011) Opportunities for conservation agriculture in the EU Common Agricultural Policy 2014-2020. In: Proceedings of the 5th World Congress of Conservation Agriculture incorporation 3rd Farming System Design Conference, Brisbane, Australia. http://aciar.gov.au/files/node/13994/opportunitiesforca_author_pdf_14070.pdf . Accessed 20 Oct 2013
5. Berner A, Hildermann A, Flieβbach PL, Niggli U, Mäder P (2008) Crop yield and soil fertility response to reduced tillage under organic management. Soil Tillage Res 101:89–96. doi: 10.1016/j.still.2008.07.012