What is the mathematics behind Facebook friend suggestion algorithms [closed]

Can anyone help me know how Facebook suggests unknown friends? Or, any references in this regards will do.

What i know is there are infinite ways in which Facebook can suggest friends. One of the ways in which Facebook suggests you friends is that when that person has mutual friends with you or that person is directly or indirectly connected your friendship networks (even if you have no mutual friends with him). In the line of this algorithm, i am thinking of a an algorithm to predict friend suggestion by Facebook using graphs and its union and intersection operations.

My problem is that, i couldn’t find any Mathematical algorithms of the mechanisms of friend suggestion by Facebook. Any reference in this regards will be appreciated.