@article{SJIM_2009_12_4_a12,
     author = {A. E. Trubacheva},
     title = {On {Optimality} of the {Flat} {Proportional} {Tax} {Rate} in {a~Two-Level} {Economic} {System}},
     journal = {Sibirskij \v{z}urnal industrialʹnoj matematiki},
     pages = {137--151},
     publisher = {mathdoc},
     volume = {12},
     number = {4},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJIM_2009_12_4_a12/}
}