WAlbertson conjecture
WBook embedding
WCovering space
WCrossing number (graph theory)
WCycle double cover
WDual graph
WGenus (mathematics)
WGraph embedding
WGraph-encoded map
WHeawood number
WPetrie dual
WQueue number
WRegular map (graph theory)
WRibbon graph
WThree utilities problem
WTopological graph
WToroidal graph
WTurán's brick factory problem
WXuong tree