TY - JOUR AU - S Heller-zeisler AU - J Ondov AU - Rolf Zeisler C2 - Biological Trace Element Research DA - 1999-12-01 00:12:00 LA - en M1 - 71-72 PB - Biological Trace Element Research PY - 1999 TI - Collection and Characterization of a Bulk PM2.5 Air Particulate Matter Material for Use in Reference Materials ER -