@article{JCA_1995_2_1-2_a16,
     author = {Pham Dinh Tao and Le Thi Hoai An},
     title = {Lagrangian {Stability} and {Global} {Optimality} in {Nonconvex} {Quadratic} {Minimization} over {Euclidean} {Balls} and {Spheres}},
     journal = {Journal of convex analysis},
     pages = {263--276},
     publisher = {mathdoc},
     volume = {2},
     number = {1-2},
     year = {1995},
     url = {http://geodesic.mathdoc.fr/item/JCA_1995_2_1-2_a16/}
}