Get reference links

def reference_links(doc):
    """Get reference links"""
    if doc.get('type') == 'organisation' and doc.get('state') != 'deactivated':
        for asset_id_type, link in doc.get('reference_links', {}).get('links', {}).items():
            value = {
                'organisation_id': doc['_id'],
                'link': link
            }
            yield asset_id_type, value