You can update your system with unsupported packages from
this untrusted PPA by adding ppa:costamagnagianfranco/firefox
to your system's Software Sources.
(Read about installing)
This PPA can be added to your system manually by copying
the lines below and adding them to your system's software
deb http://ppa.launchpad.net/costamagnagianfranco/firefox/ubuntu trusty main
deb-src http://ppa.launchpad.net/costamagnagianfranco/firefox/ubuntu trusty main
For questions and bugs with software in this PPA please contact
firefox-backports has no updates.