Norton EC, Zarkin GA, Calingaert B, Bradley CJ. The effect of maternal substance abuse on the cost of neonatal care. Inquiry. 1996;33(3):247-57.
Agha M, Gnanasakthy A. A cluster analysis of the effects of storage mites as allergens in relation to certain occupations and living conditions. Clin Allergy. 1981 Sep;11(5):499-504.