"1"^^ . . . "We show that for each integer g there is a constant Cg such that every graph that embeds in the projective plane with sufficiently large face-width r has crossing number at least Cgr^2 in the orientable surface Sg of genus g. As a corollary, we give a polynomial time constant factor approximation algorithm for the crossing number of projective graphs with bounded degree."@en . "RIV/00216224:14330/08:00024698" . . "1" . "1077-8926" . . "We show that for each integer g there is a constant Cg such that every graph that embeds in the projective plane with sufficiently large face-width r has crossing number at least Cgr^2 in the orientable surface Sg of genus g. As a corollary, we give a polynomial time constant factor approximation algorithm for the crossing number of projective graphs with bounded degree." . "Gitler, Isidoro" . . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . "The crossing number of a projective graph is quadratic in the face--width"@en . . "P(GA201/08/0308), S, Z(MSM0021622419)" . "RIV/00216224:14330/08:00024698!RIV10-GA0-14330___" . . . "crossing number; projective plane; face-width"@en . "Hlin\u011Bn\u00FD, Petr" . "Electronic Journal of Combinatorics" . "Leanos, Jesus" . "14330" . . "361595" . . "The crossing number of a projective graph is quadratic in the face--width" . "Salazar, Gelasio" . . "[56B443CBEB8C]" . "The crossing number of a projective graph is quadratic in the face--width" . "15" . . . . "000254150200003" . . . . "4"^^ . "The crossing number of a projective graph is quadratic in the face--width"@en . . "8"^^ .