Sensitivity of next-generation tritium beta-decay experiments for keV-scale sterile neutrinos. Issue 2 (17th February 2015) - Mertens, S.; Lasserre, T.; Groh, S.; Drexlin, G.; Glück, F.; Huber, A.; Poon, A.W.P.; Steidl, M.; Steinbrink, N.; Weinheimer, C.