Don’t know what the "G30" is supposed to mean, but it looks like you are looking for the
Linux Libertine fonts. Here is
more info and
the download. HTH.
The
Linux Libertine and
Libertinus (kind of a successor) fonts are actually quite nice for books and academic publications, and both have rather useful keyboard variants. I use them mainly with
LaTeX, though.
For those interested:
Libertinus on
CTAN and
GitHub.