TY - BOOK AU - Friis,Robert H. AU - Sellers,Thomas A. TI - Epidemiology for public health practice SN - 0834211785 (pbk.) AV - RA 651 .F686 1999 .F686 1999 U1 - 614.4 21 PY - 1999/// CY - Gaithersburg, Md. PB - Aspen Publishers KW - Epidemiology KW - Public health personnel KW - Public Health N1 - Includes bibliographical references and index ER -