@article{DE_1980_16_2_a5,
     author = {N. P. Erugin},
     title = {The equations $w''=f(w',w,z)$ with an irrational right-hand side},
     journal = {Differencialʹnye uravneni\^a},
     pages = {236--250},
     publisher = {mathdoc},
     volume = {16},
     number = {2},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1980_16_2_a5/}
}