Imperfect bifurcation in structures and materials : engineering use of group theoretic bifurcation theory Overview of book Imperfect behavior at simple critical points: Critical points and local behavior ; Imperfection sensitivity laws ; Worst imperfection (I) ; Random imperfection (I) ; Experimentally observed bifurcation diagrams Imperfect bifurcation of symmetric systems: Group theoretic bifurcation theory ; Bifurcation behavior of Dn equivariant systems ; Worst imperfection (II) ; Random imperfection (II) ; Description and computation of bifurcation behaviors ; Efficient transformation for block diagonalization Modeling of bifurcation phenomena: Bifurcation of cylindrical sand specimens ; Echelon mode formation ; Bifurcation of steel specimens ; Flower patterns of honeycomb structures