/** {@inheritDoc} */
  @Override
  final boolean _equals(final BibRecord r) {
    final BibTechReport x;

    if (super._equals(r)) {
      x = ((BibTechReport) r);

      return (EComparison.equals(this.m_issn, x.m_issn)
          && //
          EComparison.equals(this.m_series, x.m_series)
          && //
          EComparison.equals(this.m_number, x.m_number));
    }

    return false;
  }