By {% assign last_pos=include.authors.size | minus: 1 %} {% assign and_pos=include.authors.size | minus: 2 %} {% for i in (0..last_pos) %} {% assign author_id=include.authors[i] %} {% assign author=site.authors[author_id] %} {% if author %} <a href="mailto:{{ author.email }}">{{ author.name }}</a> {% else %} {{ author_id }} {% endif %} {% if i == and_pos %} and {% elsif i < and_pos %} , {% endif %} {% endfor %} on <span class="text-muted">{{ include.date | date_to_long_string }}</span>