@article{AFM_1980_5_2_a2,
     author = {Veikko T. Purmonen},
     title = {On parametrically quasi-elliptic boundary problems},
     journal = {Annales Fennici Mathematici},
     pages = {237--262},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1980},
     doi = {10.5186/aasfm.1980.0521},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1980.0521/}
}