@article{ZNSL_1992_202_a10,
     author = {M. N. Yakovlev},
     title = {Solvability of nonlinear systems including $(\gamma,\delta)$-comparison pairs},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {185--189},
     year = {1992},
     volume = {202},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1992_202_a10/}
}