OSTERBERG, T. Salivary flow, saliva, pH and buffering capacity in 70-years-old men and women. Correlation to dental health, dryness in the mouth, disease and drug treatment. J. Oral Rehab. 1984, 11, 157-170
THOMSON, W. M. The occurrence of xerostomia and salivary gland hypofunction in a population-based sample of older South Australians. Spec. Care Dentist. 1999, 1920-1923