TY - JOUR AU - Kevin Coakley AU - A Leifer AU - David Simons C2 - Intl. J. Mass Spectrometry DA - 2005-01-15 00:01:00 LA - en M1 - 240 PB - Intl. J. Mass Spectrometry PY - 2005 TI - Secondary ion mass spectrometry measurements of isotopic ratios: Correction for time varying count rates ER -