APPLIED PHYSICS LETTERS, vol. 75, no. 16, page. 2377 - 2379, 1999-10-18
JOURNAL OF APPLIED PHYSICS, vol. 86, no. 8, page. 4613 - 4618, 1999-10-15
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, vol. 437, no. 2-3, page. 516 - 520, 1999-11-21