Round robin performance testing of organic photovoltaic devices - Gevorgyan,SA; Zubillaga,O; Maria,Vega de Seoane J; Machado,M; Parlak,EA; Tore,N; Voroshazi,E; Aernouts,T; Muellejans,H; Bardizza,G; Taylor,N; Verhees,W; et al. (RENEWABLE ENERGY, 2014)