The International Soil Moisture Network: a data hosting facility for global in situ soil moisture measurements. - Dorigo, W. A.; Wagner, W.; Hohensinn, R.; Hahn, S.; Paulik, C.; Xaver, A.; Gruber, A.; Drusch, M.; Mecklenburg, S.; van Oevelen, P.; Robock, A.; Jackson, T. (Hydrology & Earth System Sciences, 2011)