TY - JOUR T1 - Viability of f(R) theories with additional powers of curvature JO - PHYS REV D PY - 2006/09/01 AU - Brookfield AW AU - van de Bruck C AU - Hall LMH ED - DO - DOI: 10.1103/PhysRevD.74.064028 VL - 74 IS - 6 Y2 - 2024/12/26 ER -