Ground state features of the Fröhlich modelG. De Filippis, V. Cataudella, V. Marigliano Ramaglia, C. A. Perroni and D. BerciouxEur. Phys. J. B, 36 1 (2003) 65-73DOI: https://doi.org/10.1140/epjb/e2003-00317-x