Confinement potential in the dual monopole Nambu–Jona–Lasinio model with dual Dirac strings M. Faber, A.N. Ivanov, A. Müller, N.I. Troitskaya and M. Zach Eur. Phys. J. C, 10 3 (1999) 537-544 Published online: 12 August 1999 DOI: 10.1007/s100520050776