Pach, János; Tóth, Géza (1997), „Graphs drawn with few crossings per edge“, Combinatorica, 17-jild, № 3, 427–439-bet, doi:10.1007/BF01215922, S2CID20480170.
Pach, János; Tóth, Géza (1997), „Graphs drawn with few crossings per edge“, Combinatorica, 17-jild, № 3, 427–439-bet, doi:10.1007/BF01215922, S2CID20480170.