Orbital solutions of eight close sdB binaries and constraints on the nature of the unseen companions. - Geier, S.; Østensen, R. H.; Heber, U.; Kupfer, T.; Maxted, P. F. L.; Barlow, B. N.; Vučković, M.; Tillich, A.; Müller, S.; Edelmann, H.; Classen, L.; McLeod, A. F. (Astronomy & Astrophysics / Astronomie et Astrophysique, 2014)