anchor.diff:                  <div class="col s12 m6 l4">
                       <a name="${storyBook.id}"></a>
                       <div class="storyBook card">
  -                        <a href="<spring:url value='/content/storybook/edit/${storyBook.id}' />">
  -                            <div class="card-image" style="background-image: url(<spring:url value='/image/${storyBook.coverImage.id}_r${storyBook.coverImage.revisionNumber}.${fn:toLowerCase(storyBook.coverImage.imageFormat)}' />);">
  -                                <span class="card-title"><c:out value="${storyBook.title}" /></span>
  -                            </div>
  -                        </a>
  +                        <c:if test="${not empty storyBook.coverImage}">
  +                            <a href="<spring:url value='/content/storybook/edit/${storyBook.id}' />">
  +                                <div class="card-image" style="background-image: url(<spring:url value='/image/${storyBook.coverImage.id}_r${storyBook.coverImage.revisionNumber}.${fn:toLowerCase(storyBook.coverImage.imageFormat)}' />);">
  +                                    <span class="card-title"><c:out value="${storyBook.title}" /></span>
  +                                </div>
  +                            </a>
  +                        </c:if>
                           <div class="card-content">
                               <p class="grey-text" style="margin-bottom: 0.5em;"><c:out value="${storyBook.description}" /></p>
                               <p><fmt:message key="reading.level.${storyBook.readingLevel}" /></p>
  
positive.code:             <div class="col s12 m6 l4">
                  <a name="${storyBook.id}"></a>
                  <div class="storyBook card">
                      <a href="<spring:url value='/content/storybook/edit/${storyBook.id}' />">
                          <div class="card-image" style="background-image: url(<spring:url value='/image/${storyBook.coverImage.id}_r${storyBook.coverImage.revisionNumber}.${fn:toLowerCase(storyBook.coverImage.imageFormat)}' />);">
                              <span class="card-title"><c:out value="${storyBook.title}" /></span>
                          </div>
                      </a>
                      <div class="card-content">
                          <p class="grey-text" style="margin-bottom: 0.5em;"><c:out value="${storyBook.description}" /></p>
                          <p><fmt:message key="reading.level.${storyBook.readingLevel}" /></p>
  
negative.code:             <div class="col s12 m6 l4">
                  <a name="${storyBook.id}"></a>
                  <div class="storyBook card">
                      <c:if test="${not empty storyBook.coverImage}">
                          <a href="<spring:url value='/content/storybook/edit/${storyBook.id}' />">
                              <div class="card-image" style="background-image: url(<spring:url value='/image/${storyBook.coverImage.id}_r${storyBook.coverImage.revisionNumber}.${fn:toLowerCase(storyBook.coverImage.imageFormat)}' />);">
                                  <span class="card-title"><c:out value="${storyBook.title}" /></span>
                              </div>
                          </a>
                      </c:if>
                      <div class="card-content">
                          <p class="grey-text" style="margin-bottom: 0.5em;"><c:out value="${storyBook.description}" /></p>
                          <p><fmt:message key="reading.level.${storyBook.readingLevel}" /></p>
  