Building a Soil Information Portal for Europe based on the PortalU Technology. - Katharina Feiden; Martin Klenke; Fred A. Kruse; Stefanie Konstantinidis (EnviroInfo (1), 2009)

Current state of the German Environmental Information Portal PortalU®. - Stefanie Konstantinidis; Fred A. Kruse; Martin Klenke (EnviroInfo (1), 2009)

PortalU®, a Tool for Building a Single Information Space in Europe (SISE) for the Environment. - Fred A. Kruse; Stefanie Konstantinidis; Martin Klenke (EnviroInfo (1), 2009)

Some thoughts to realignment of PortalU. - Stefanie Konstantinidis; Fred A. Kruse (EnviroInfo, 2013)