@article{ZNSL_2006_330_a4,
     author = {S. V. Vostokov and B. M. Bekker},
     title = {Distinguished isogenies for formal groups in local fields with small ramification},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {93--100},
     publisher = {mathdoc},
     volume = {330},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2006_330_a4/}
}