@book{icrisat553,
       publisher = {International Crops Research Institute for the Semi-Arid Tropics},
          editor = {G O Omanya and D Pasternak},
         address = {Niamey, Niger},
            year = {2005},
           title = {Sustainable Agriculture Systems for the Drylands.
Proceedings of the International Symposium for Sustainable Dryland Agriculture Systems, 2?5 December 2003, Niamey, Niger},
             url = {http://oar.icrisat.org/553/}
}