Multifunctionality: epistemic diversity and concept oriented research clusters. - Caron, Patrick; Reig, Ernest; Roep, Dirk; Hediger, Werner; Le Cotty, Tristan; Barthelemy, Denis; Hadynska, Anna; Hadynski, Jakub; Oostindie, Henk A.; Sabourin, Eric (International Journal of Agricultural Resources, Governance & Ecology, 2008)