Daniels TB, Brown PD, Felten SJ, Wu W, Buckner JC, Arusell RM, Curran WJ, Abrams RA, Schiff D, Shaw EG. Validation of EORTC prognostic factors for adults with low-grade glioma: a report using intergroup 86-72-51. Int J Radiat Oncol Biol Phys. 2011 Sep 01; 81(1):218-24.