@article{03889961, title = {On the asymptotic series solution of some higher order linear differential equations at turning points.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {7}, year = {1984}, pages = {541-548}, doi = {10.1155/S0161171284000600}, zbl = {0558.34050}, language = {en}, url = {http://dml.mathdoc.fr/item/03889961} }
Gorman, Arthur D. On the asymptotic series solution of some higher order linear differential equations at turning points.. International Journal of Mathematics and Mathematical Sciences, Tome 7 (1984) pp. 541-548. doi : 10.1155/S0161171284000600. http://gdmltest.u-ga.fr/item/03889961/