@article{DEME_1979__20_a13, author = {E. C. Zachmanoglou}, title = {Solutions which are flat or {Singular} on {Totally} {Characteristic} {Manifolds} of first order {Partial} {Differential} {Equations} }, journal = {\ensuremath{\Delta}\ensuremath{\varepsilon}\ensuremath{\lambda}\ensuremath{\tau}\ensuremath{\acute\iota}o \ensuremath{\tau}\ensuremath{\eta}\ensuremath{\varsigma} E\ensuremath{\lambda}\ensuremath{\lambda}\ensuremath{\eta}\ensuremath{\nu}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\eta}\ensuremath{\varsigma} M\ensuremath{\alpha}\ensuremath{\theta}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\eta}\ensuremath{\varsigma} E\ensuremath{\tau}\ensuremath{\alpha}\ensuremath{\iota}\ensuremath{\rho}\ensuremath{\acute\iota}\ensuremath{\alpha}\ensuremath{\varsigma} }, pages = {149-158}, publisher = {mathdoc}, volume = {20}, year = {1979}, language = {gr}, url = {http://geodesic.mathdoc.fr/item/DEME_1979__20_a13/} }