2007 · P. Klocke, Ophélie Clottu, et al. · Organic Eprints (International Centre for Research in Organic Food Systems, and Research Institute of Organic Agriculture)
2007 · Ophélie Clottu, Peter Klocke, et al. · Organic Eprints (International Centre for Research in Organic Food Systems, and Research Institute of Organic Agriculture)
2006 · Ophélie Clottu, Peter Klocke, et al. · Organic Eprints (International Centre for Research in Organic Food Systems, and Research Institute of Organic Agriculture)