<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<div class="container">
<div class="row">
<div class="col-md-4">
<div class="card mb">
<img class="card-img-top" src="http://www.placehold.it/286x180" alt="Card image cap">
<div class="card-body mb">
<h5 class="card-title">Card title</h5>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
<button type="button" class="btn btn-primary mb">button</button>
</div>
</div>
</div>
<div class="col-md-4">
<div class="card mb">
<img class="card-img-top" src="http://www.placehold.it/286x180" alt="Card image cap">
<div class="card-body mb">
<h5 class="card-title">Card title</h5>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
<button type="button" class="btn btn-primary mb">button</button>
</div>
</div>
</div>
<div class="col-md-4">
<div class="card mb">
<img class="card-img-top" src="http://www.placehold.it/286x180" alt="Card image cap">
<div class="card-body mb">
<h5 class="card-title">Card title</h5>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
<button type="button" class="btn btn-primary mb">button</button>
</div>
</div>
</div>
</div>
</div>
</div>
</div>