Erich Schikuta Thomas Weishäupl Flavia Donno Heinz Stockinger Elisabeth Vinek Helmut Wanek Christoph Witzany Irfan Ul Haq http://arxiv.org/abs/0909.2055 2009 CoRR abs/0909.2055 db/journals/corr/corr0909.html#abs-0909-2055 informal publication