TY - CONF A1 - Schmidt, Anita T1 - Added value of PT/EQA and cost benefit evaluation T2 - 4th International Workshop on Proficiency Testing in Analytical Chemistry, Microbiology and Laboratory Medicine T2 - 4th International Workshop on Proficiency Testing in Analytical Chemistry, Microbiology and Laboratory Medicine CY - Bracknell, England DA - 2003-02-16 PY - 2003 AN - OPUS4-5093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -