Editing Planar graph (section)

===Word-representable planar graphs===
[[Word-representable graph|Word-representable]] planar graphs include triangle-free planar graphs and, more generally, 3-colourable planar graphs,<ref name="HK|last=P16">{{cite journal |first1=M. |last1=Halldórsson |first2=S. |last2=Kitaev |first3=A. |last3=Pyatkin. |title=Semi-transitive orientations and word-representable graphs |journal=Discr. Appl. Math.  |volume=201  |issue= |pages=164–171  |doi= 10.1016/j.dam.2015.07.033|date=2016 |s2cid=26796091 |doi-access=free |url=https://strathprints.strath.ac.uk/54148/2/Halldorsson_etal_DAM_2015_Semi_transitive_orientations_and_word_representable.pdf }}</ref> as well as certain face subdivisions of triangular grid graphs,<ref name="CKS2016">{{cite journal |arxiv=1503.08002 |first1=T. Z. Q. |last1=Chen |first2=S. |last2=Kitaev |first3=B. Y. |last3=Sun |title=Word-representability of face subdivisions of triangular grid graphs |journal=Graphs and Combin |volume=32 |issue=5 |pages=1749–61 |date=2016 |doi= 10.1007/s00373-016-1693-z|s2cid=43817300 |url=}}</ref> and certain triangulations of grid-covered cylinder graphs.<ref name="CKS2016-2">{{cite journal |arxiv=1507.06749 |first1=T. Z. Q. |last1=Chen |first2=S. |last2=Kitaev |first3=B. Y. |last3=Sun |title=Word-representability of triangulations of grid-covered cylinder graphs |journal=Discr. Appl. Math. |volume=213 |issue= |pages=60–70 |date=2016 |doi= 10.1016/j.dam.2016.05.025|s2cid=26987743 |url=}}</ref>