Bernabei R., Landi F., Gambassi G., Sgadari A., Zuccala G., Mor V., Rubenstein L.Z, Carbonin P..  1998.  Randomised trial of impact of model of integrated care and case management for older people living in the community. Bmj. 316(7141):1348-51.

Karon S.L, Sainfort F., Zimmerman D.R.  1999.  Stability of nursing home quality indicators over time. Medical Care. 37(6):570-9.