.col-sm-4
.col-sm-6.offset-sm-2

<div class="row">
    <div class="col-sm-4">
        <span>.col-sm-4</span>
    </div>
    <div class="col-sm-6 offset-sm-2">
        <span>.col-sm-6.offset-sm-2</span>
    </div>
</div>