TY  - JOUR
AU  - Mattman, Thomas W
TI  - Graphs of 20 edges are 2–apex, hence unknotted
JO  - Algebraic and Geometric Topology
PY  - 2011
SP  - 691
EP  - 718
VL  - 11
IS  - 2
UR  - http://geodesic.mathdoc.fr/articles/10.2140/agt.2011.11.691/
DO  - 10.2140/agt.2011.11.691
ID  - 10_2140_agt_2011_11_691
ER  -