http://www.graphviz.org/pdf/dotguide.pdf
https://graphs.grevian.org/reference
http://zhangliyong.github.io/posts/2014/02/23/graphviz-tutorial.html
https://renenyffenegger.ch/notes/tools/Graphviz/examples/index
https://graphviz.gitlab.io/_pages/doc/info/shapes.html#html
https://graphviz.gitlab.io/faq/#FaqCustShape
https://github.com/mountainstorm/jquery.graphviz.svg
https://argdown.org/guide/changing-the-graph-layout.html#layouting-with-viz-js
https://forum.graphviz.org/t/layout-in-vertical-column-with-side-notes/290/3
https://stackoverflow.com/questions/2467450/control-layout-using-graphviz-twopi
https://graphviz.readthedocs.io/en/stable/manual.html#engines
https://mikemol.github.io/graphviz/dot/2018/02/27/graphviz-dot-basics-pt-2.html
