Bootstrap Cards - Show random

I will try it in my best english and hope u will understand. We want to show 4 Bootstrap Cards in a row. This is easy and works already.

Our problem is, that we have more than 4 Cards and we want to show them randomly when the user loads the webpage.

For example we have 12 cards. When the user loads the webpage the first time they will see card number

1 - 4 - 7 - 12

When they reload they will see

2 - 5 - 6 - 11

and so on... how does this work? i just found the following example, that will show cards random but not just 4 of them:

[Google](http://jsfiddle.net/BwJHj/1/)