<a href="img/img-01.jpg" data-lightbox="group"><img src="img/img-01-small.jpg"></a>
<a href="img/img-02.jpg" data-lightbox="group"><img src="img/img-02-small.jpg"></a>
<a href="img/img-03.jpg" data-lightbox="group"><img src="img/img-03-small.jpg"></a>
<a href="img/img-04.jpg" data-lightbox="group"><img src="img/img-04-small.jpg"></a>