Abstract (2011) - E Friis-Christensen (author), R Floberghagen (author), G Plank (author), N Olsen (author), G Hulot (author), A Kuvshinov (author), V Lesur (author), A Thomson (author), Pieter Visser (author), P. Visser (author), P.N.A.M. Visser (author), Pieter N. A. M. Visser (author), Pieter N.A.M. Visser (author), PNAM Visser (author), P. N.A.M. Visser (author)