@article{SM_2001_192_11_a2,
     author = {S. V. Lapin},
     title = {Differential perturbations and $D_\infty$-differential modules},
     journal = {Sbornik. Mathematics},
     pages = {1639--1659},
     publisher = {mathdoc},
     volume = {192},
     number = {11},
     year = {2001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2001_192_11_a2/}
}