The pion-nucleon scattering lengths
from pionic hydrogen and deuterium
H.-Ch. Schröder, A. Badertscher, P. F.A. Goudsmit, M. Janousch, H. J. Leisi, E. Matsinos, D. Sigg, Z. G. Zhao, D. Chatellard, J.-P. Egger, K. Gabathuler, P. Hauser, L. M. Simons and A.J. Rusi El Hassani
Eur. Phys. J. C, 21 3 (2001) 473-488
DOI: https://doi.org/10.1007/s100520100754