Knispel, Benjamin Observational Relativity and Cosmology, AEI-Hannover, MPI for Gravitational Physics, Max Planck Society;
http://www.sterne-und-weltraum.de/alias/klimaforschung/happy-birthday-grace/1146147 (Publisher version)
Knispel, B. (2012). Happy Birthday, GRACE! Sterne und Weltraum: ASTROnews.