Fries B.E, Mehr D.R, Schneider D., Foley W.J, Burke R..  1993.  Mental dysfunction and resource use in nursing homes. Medical Care. 31(10):898-920.

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.

Fries B.E, Schneider D.P, Foley W.J, Gavazzi M., Burke R., Cornelius E..  1994.  Refining a case-mix measure for nursing homes: Resource Utilization Groups (RUG-III). Medical Care. 32(7):668-85.

Schneider D.P, Fries B.E, Foley W.J, Desmond M., Gormley W.J.  1988.  Case mix for nursing home payment: resource utilization groups, version II. Health Care Financing Review. Spec(No):39-52.

Williams B.C, Fries B.E, Foley W.J, Schneider D., Gavazzi M..  1994.  Activities of daily living and costs in nursing homes. Health Care Financing Review. 15(4):117-35.