@article{PORMA_1988__45_4_115637,
     author = {Eastham, M.S.P.},
     title = {The asymptotic solution of higher-order differential equations with small final coefficient},
     journal = {Portugaliae mathematica},
     pages = {351--362},
     publisher = {mathdoc},
     volume = {45},
     number = {4},
     year = {1988},
     mrnumber = {0982904},
     zbl = {0676.34036},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1988__45_4_115637/}
}