On thermodynamic stability of heteropolymer mesophases formed under weak segregation regime S. I. Kuchanov, M. A. Livshits and V. E. Pichugin Eur. Phys. J. B, 58 1 (2007) 69-82 Published online: 28 July 2007 DOI: 10.1140/epjb/e2007-00199-x