Rantz, M. J., Mehr, D. R., Petroski, G. F., Madsen, R. W., Popejoy, L. L., Hicks, L. L., Conn, V. S., Grando, V. T., Wipke-Tevis, D. D., Bostick, J., Porter, R., Zwygart-Stauffacher, M., Maas, M. 2000. Initial field testing of an instrument to measure: observable indicators of nursing home care quality. Journal of Nursing Care Quality. 14 (3) 1-12.