Remove platform-api.sharethis.com/js/

Hi

I once used the free plugin sharethis.

After uninstalling (cleared cache etc.)

I still see:

https://platform-api.sharethis.com/js/sharethis.js

and

https://buttons-config.sharethis.com/js/58c981dd783e4a0012a5337d.js

Popping up in my google pagespeed test and when I test on tool.pingdom.com

Is there a way I can add some code in my files do remove the leftovers of this plugin?