@article{ZNSL_1983_124_a2,
     author = {T. A. Tushkina},
     title = {Calculation of lower bound of schedule length},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {35--40},
     year = {1983},
     volume = {124},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1983_124_a2/}
}