@article{10_4153_CMB_1961_027_6,
     author = {Swanson, C. A.},
     title = {On a {Non-Analytic} {Perturbation} {Problem}},
     journal = {Canadian mathematical bulletin},
     pages = {243--248},
     year = {1961},
     volume = {4},
     number = {3},
     doi = {10.4153/CMB-1961-027-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1961-027-6/}
}