https://cwillberg.github.io/Materialbibliothek/dev/
https://cwillberg.github.io/Materialbibliothek/dev/metalle/eisen/
https://cwillberg.github.io/Materialbibliothek/dev/kunststoffe/PMMA/
https://cwillberg.github.io/Materialbibliothek/dev/naturwerkstoffe/holz/