This is a very simple way of finding fonts that you would normally have to pay hundreds of dollars for - for free. You may already know this but if not then - enjoy!
I have never NOT found the font I need this way.
Step one - find out the name of the font you require in this example Avenir that costs a whopping £303 for the full set!!
Step two - Go to Google and search "github" fontname.ttf:
Step three - So many choices! Click the one you want and you will land on the github page and simple click download:
If you are after all the version click on the fonts folder in the breadcrumbs and you will see all of them!
If you found this useful thank me :D !!