group

<div>
    <br/>
    <c:group name="list" key="author,firstName,lastName" row="author" id="titles">
        <h2>${author.firstName} ${author.lastName}</h2>
        <ul>
            <c:list name="titles" id="book">

                <li>${book.title}</li>

            </c:list>
        </ul>
        <br/>
    </c:group>
</div>