Ambus, Per (2007) Økologisk bioenergi og drivhusgasser. [Organic bioenergy and greenhouse gases.] In: Økologisk Jordbrug, November 2007.
Ambus, Per (2009) Klimavenlig majs ved minimal tilførsel af kvælstof. [Climate change friendly maize with reduced nitrogen applications.] In: Landbrugsavisen, April 2009.
Carter, Mette S.; Johansen, Anders; Haugaard-Nielsen, Henrik and Ambus, Per (2008) Consequences of agro-biofuel production for greenhouse gas emissions. EnergyDTU Internal Conference, Technical University of Denmark, Lyngby, Denmark, 11 December.
Hauggaard-Nielsen, H; Ambus, P; Dalgaard, T; Johansen, A; Jørgensen, U; Nielsen, A.M.; Nielsen, L.H.; Olesen, J.E.; Roepstorff, A; Skytte, K; Smith, J.E.; Thomsen, A.B.; Thomsen, M.H. and Jensen, E.S. (2007) Biomass and bioenergy production in organic agriculture. Consequences for soil fertility, environment, spread of animal parasites and socio-economy. BioConcnes, a 4-year interdisciplinary project. 23rd NJF Congres, Faculty of Life Sciences, University of Copenhagne, Denmark, 26-29 June, 2007. [ Unpublished]
Hauggaard-Nielsen, Henrik; Jensen, Erik Steen; Carter, Mette S.; Johansen, Anders and Ambus, Per (2009) Strip intercropping strategy for biomass to energy production while on the same time maintaining soil fertility. NJF seminar 428: Energy conversion from biomass production - EU-AgroBiogas, Viborg, Denmark, 9-10 September, 2009. In: NJF Report, Vol. 5, No 3, Year 2009, NJF General Secretariat, Stockholm, Sweden.
Johansen, A.; Hauggaard-Nielsen, H.; Ambus, P.; Dalgaard, T.; Jørgensen, U.; Nielsen, A.M.; Nielsen, L.H.; Olesen, J.E.; Roepstorff, A.; Skytte, K.; Smith, J.E.; Thomsen, A.B.; Carter, M.S. and Jensen, E.S. (2008) Production of biomass and bioenergy in organic agriculture and its consequences for soil quality, environment, biodiversity and socio-economy. [Produktion af biomasse og bioenergi i økologisk jordbrug og konsekvenserne for jord kvalitet, miljø, biodiversitet og socio-økonomi.] ALTERNET Workshop: Interlinkage between Biodiversity and Bioenergy, Edinburgh, 20th - 21st October 2008.
Johansen , Anders; Hauggaard-Nielsen, Henrik; Ambus, Per and Carter, Mette S. (2009) Recycling of bioenergy waste-stream materials to soil in organic farming systems. NJF Seminar 422 , Tartu in Estonia, 25-27 August 2009.
Oleskowicz-Popiel, P; Ambus, P; Carter, M.S.; Dalgaard, T.; Hauggaard-Nielsen, H; Johansen, A; Jørgensen, U; Nielsen, A.M; Nielsen, H.B.; Nielsen, L.H; Olesen, J.E.; Roepstorff, A; Skytte, K; Schmidt, J.E.; Thomsen, A.B.; Thomsen, M.H. and Jensen, E.S. (2008) BioConcens: Biomass and bioenergy production agriculture – consequences for soil fertility, environment, spread of animal parasites and socio-economy. vth International Symposium on anaerobic digestion of solid wastes and energy crops.