@article{ZNSL_1997_249_a8,
     author = {N. M. Ivochkina},
     title = {Mini survey of the principal notions in the theory of fully nonlinear elliptic second-order differential equations},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {199--211},
     publisher = {mathdoc},
     volume = {249},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1997_249_a8/}
}