Gimli: Box2D source upload

I've been trying to get *release* tarball of Box2D physics engine as stated
by tml_ on IRC channel. I need to send the link to tarball to members
having access to gimli so that a new library can be added to libreoffice.
But I can't find any release tarball of it but one.
https://github.com/erincatto/Box2D/tarball/master , it is github repo
tarball link. I read on stackoverflow to add /tarball/master to link and
tarball will be downloaded. Will that work for gimli? If this will not work
please tell me what is release tarball so that if it doesn't workout with
Box2D, I can choose a different physics engine.
Thank You


Regards,
Mayank