@article{IM_1991__105_3_143918,
     author = {Steven C. Ferry and Shmuel Weinberger},
     title = {Curvature, tangentiality, and controlled topology.},
     journal = {Inventiones mathematicae},
     pages = {401--414},
     publisher = {mathdoc},
     volume = {105},
     number = {3},
     year = {1991},
     zbl = {0744.57017},
     url = {http://geodesic.mathdoc.fr/item/IM_1991__105_3_143918/}
}