1. H. Ahola, T. Luntama, K. Viherkanto, T. Ylikorpi, V. Heikkinen, M. Aikio, K. Keränen, J.-T. Mäkinen, V.-P. Aarnio, A. Halme, P. Jakubik, M. Savela, J. Suomela, J. Heimsch, ITER in-vessel viewing system prototype campaign, Proceedings of the 20th SOFT, Fusion Technology (Association EURATOM-CEA), vol. 2, Marseilles, France, 1998, pp. 1051–1054.