biblio_delete needs to require biblio.keywords.inc

/**
 * Implementation of hook_delete().
 *
 * When a node is deleted, we need to clean up related tables.
 */
function biblio_delete($node) {
+  require_once(drupal_get_path('module', 'biblio') .'/biblio.keywords.inc');
  //first remove data from the biblio table
  db_query('DELETE FROM {biblio} WHERE nid = %d', $node->nid);
  biblio_delete_contributors($node);
  biblio_delete_keywords($node);
}

If I call this function from another module it's possible that I get a fatal function not found error.