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@article{DE_1980_16_10_a18, author = {L. N. Lyapin}, title = {Upper and lower solution of equations of evolution type}, journal = {Differencialʹnye uravneni\^a}, pages = {1885--1887}, publisher = {mathdoc}, volume = {16}, number = {10}, year = {1980}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1980_16_10_a18/} }
L. N. Lyapin. Upper and lower solution of equations of evolution type. Differencialʹnye uravneniâ, Tome 16 (1980) no. 10, pp. 1885-1887. http://geodesic.mathdoc.fr/item/DE_1980_16_10_a18/