Ian T. Foster Veronika Nefedova Mehran Ahsant Rachana Ananthakrishnan Lee Liming Ravi K. Madduri Olle Mulmo Laura Pearlman Frank Siebenlist Streamlining Grid Operations: Definition and Deployment of a Portal-based User Registration Service. 135-144 2006 4 J. Grid Comput. 2 http://dx.doi.org/10.1007/s10723-006-9047-3 db/journals/grid/grid4.html#FosterNAALMMPS06