TY - BOOK AU - Friis,Robert H. AU - Sellers,Thomas A. TI - Epidemiology for public health practice SN - 0834206080 U1 - WA 105 PY - 1996/// CY - Gaithersburg, Md. PB - Aspen Publishers KW - Epidemiology KW - Public Health N1 - Includes an Index; ER -