Masses of light tetraquarks and scalar mesons in the relativistic quark model D. Ebert, R. N. Faustov and V. O. Galkin Eur. Phys. J. C, 60 2 (2009) 273-278 Published online: 13 February 2009 DOI: 10.1140/epjc/s10052-009-0925-2