@misc{FreydankSiebert2008,
  author    = {Katharina Freydank and Stefan Siebert},
  title     = {Towards mapping the extent of irrigation in the last century : time series of irrigated area per country},
  institution = {Geowissenschaften},
  series    = {Frankfurt Hydrology Paper},
  number    = {08},
  year      = {2008}
}