1. The MINOS Collab., The Hybrid Emulsion Detector for MINOS R&D Proposal, NuMI-L-473 (April 1999).
2. The OPERA Collab., A Long Baseline v, Appearance Experiment in the CNGS Beam from CERN to Gran Sasso (Progress Report), CERN/SPSC. 99-20, SPSC/M635, LNGS-LOI 19/99 (August 27, 1999).
3. Yu. D. Aleshin, V. V. Kolesnikov, and V. I. Silaev, Prib. Tekh. Éksp., No. 2, 43 (1997).
4. S. Z. Belen’kii and I. V. Ivanenko, Usp. Fiz. Nauk 69, 591 (1959) [Sov. Phys. Usp. 2, 912 (1959)].
5. J. Butcher and H. Messel, Nucl. Phys. 20, 15 (1960).