The shape of the radio wavefront of extensive air showers as measured with LOFAR par Corstanje, A, Schellart, P, Nelles, A, Buitink, S, Enriquez, J, Falcke, H, Frieswijk, W, Horandel, JR, Krause, M, Rachen, J, Scholten, O, ter Veen, S, Thoudam, S, Trinh, T, van den Akker, M, Alexov, A, Anderson, J, Avruch, I, Bell, M, Bentum, M, Bernardi, G, Best, P, Bonafede, A, Breitling, F, Broderick, J, Bruegen, M, Butcher, H, Ciardi, B, de Gasperin, F, de Geus, E, de Vos, M, Duscha, S, Eisloeffel, J, Engels, D, Fallows, R, Ferrari, C, Garrett, M, Griessmseier, J, Gunst, A, Hamaker, J, Hoeft, M, Homeffer, A, Icobelli, M, Juette, E, Karastergiou, A, Kohler, J, Kondratiev, V, Kuniyoshi, M, Kuper, G, Maat, P, Mann, G, McFadden, R, McKay-Bukowski, D, Mevius, M, Munk, H, Norden, M, Orru, E, Paas, H, Pandey-Pommier, M, Pandey, V, Pizzo, R, Polatidis, A, Reich, W, Rottgering, H, Scaife, A, Schwarz, D, Smirnov, O, Stewart, A, Steinmetz, M, Swinbank, J, Tagger, M, Tang, Y, Tasse, C, Toribio, C, Vermeulen, R, Vocks, C, van Weeren, R, Wijnholds, S, Wucknitz, O, Yatawatta, S, Zarka, P