@article{PSMIR_1977___S4_A11_0,
     author = {Nitsche, J. A.},
     title = {Least {Squares} {Approximations} to {First} {Order} {Elliptic} {Systems}},
     journal = {Publications de l'Institut de recherche math\'ematiques de Rennes},
     eid = {11},
     pages = {1--14},
     publisher = {D\'epartement de Math\'ematiques et Informatique, Universit\'e de Rennes},
     number = {S4},
     year = {1977},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PSMIR_1977___S4_A11_0/}
}