Modified spin-wave theory for the S = 1 frustrated antiferromagnetic Heisenberg chainG. M. Rocha-Filho, A. S.T. Pires and M. E. GouvêaEur. Phys. J. B, 56 1 (2007) 7-14DOI: https://doi.org/10.1140/epjb/e2007-00082-x