{% if reference_a != reference_b %} {% if reference_a and reference_b %} {# Reference has changed #}
{{ reference_a.bibtex }}
{{ reference_b.bibtex }}
{% elif reference_b %} {# Reference has been added #}
{{ reference_b.bibtex }}
{% elif reference_a %} {# Reference has been removed #}
{{ reference_a.bibtex }}
{% endif %} {% else %}
{% if reference_a %} {{ reference_a.bibtex }} {% else %}
{% endif %}
{% endif %}