@article{DE_2004_40_12_a13,
     author = {I. P. Martynov and G. T. Mozhdzher},
     title = {On first integrals of a fourth-order equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1701--1704},
     publisher = {mathdoc},
     volume = {40},
     number = {12},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2004_40_12_a13/}
}