@article{IM2_1967_1_4_a1,
     author = {Ya. I. Zhitomirskii},
     title = {Uniqueness classes of solutions of the {Cauchy} problem for linear
},
     journal = {Izvestiya. Mathematics },
     pages = {737--756},
     publisher = {mathdoc},
     volume = {1},
     number = {4},
     year = {1967},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1967_1_4_a1/}
}