Fries B.E, Schneider D.P, Foley W.J, Dowling M..  1989.  Case-mix classification of Medicare residents in skilled nursing facilities: resource utilization groups (RUG-T18). Medical Care. 27(9):843-58.

Grabowski D.C, Zhanlian F, Mor V..  2008.  Medicaid nursing home payment and the role of provider taxes. Med Care Res Rev. 65(4):514-27.