Gastrointestinal Transit of a Magnetically Marked Capsule Monitored Using a 37-Channel SQUID-Magnetometer W. Weitschies, R. Kötitz, L. Trahms et D. Cordini J. Phys. IV France, 07 C1 (1997) C1-667-C1-668 DOI: 10.1051/jp4:19971272