private function gedcomHead(): array
    {
        $title   = '';
        $version = '';
        $source  = '';

        $head = GedcomRecord::getInstance('HEAD', $this->tree);

        if ($head instanceof GedcomRecord) {
            $sour = $head->facts(['SOUR'])->first();

            if ($sour instanceof Fact) {
                $source  = $sour->value();
                $title   = $sour->attribute('NAME');
                $version = $sour->attribute('VERS');
            }
        }

        return [
            $title,
            $version,
            $source,
        ];
    }