How to add social share button for each post?

Hi,
my theme haven’t the social share button for each post; how can add social share button (google+, facebook, twitter, linkedin… like here: http://searchengineland.com/paid-search-study-bings-click-traffic-growing-faster-than-googles-138335)?

With Plugin?

I’ve tried “most shared post”, “social media widget” and “wordpress seo” plugin but don’t seem to be suitable for this purpose..

Can you help me please?

Thanks,
bye bye!