Hauggaard-Nielsen, Henrik; Thomsen, Mette Hedegaard and Jensen, Erik Steen (2009) Why diversify annual biomass production for energy – exemplified by green house gas emissions from the Danish IBUS bioethanol production concept. Proceedings of NJF Seminar 405: Production and utilization of crops for energy, Vilnius, Lithuania, 25-26 September, 2007. NJF General Secretariat, Stockholm, Sweden. ISBN 1653-2015