Ikegami, N., Fries, B. E., Takagi, Y., Ikeda, S., Ibe, T. 1994. Applying RUG-III in Japanese long-term care facilities. Gerontologist. 34 (5) 628-39.
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.