@article{IM2_1975_9_6_a0,
     author = {M. I. Bashmakov and A. N. Kirillov},
     title = {Lutz filtration of formal groups},
     journal = {Izvestiya. Mathematics},
     pages = {1155--1167},
     year = {1975},
     volume = {9},
     number = {6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1975_9_6_a0/}
}