Phase transitions and interface fluctuations in double wedges and bi-pyramids with competing surface fieldsM. Müller, A. Milchev, K. Binder and D. P. LandauEur. Phys. J. B, 64 3-4 (2008) 499-503DOI: https://doi.org/10.1140/epjb/e2008-00021-5