Four zero texture fermion mass matrices in SO(10) GUT S. Dev, Sanjeev Kumar, Surender Verma, Shivani Gupta and R.R. Gautam Eur. Phys. J. C, 72 3 (2012) 1940 Published online: 21 March 2012 DOI: 10.1140/epjc/s10052-012-1940-2