@article{DE_1971_7_6_a2,
     author = {N. S. Erokhin},
     title = {An asymptotic expansion of the solutions of the equation $y^{\mathrm{IV}}+(\lambda+\xi^2)y^{\mathrm{II}}\mu y=0$ 
},
     journal = {Differencialʹnye uravneni\^a},
     pages = {970--980},
     publisher = {mathdoc},
     volume = {7},
     number = {6},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1971_7_6_a2/}
}