15 public static $DOI_PLUS;
17 private static $initialized =
false;
27 if (self::$initialized ==
false) {
34 self::$initialized =
true;
46 $this->code = $code < 1 || $code > 6 ? 6 : $code;
48 $this->type = $this->getType($code);
78 private function getType($code) {
125 return self::$DOI_PLUS;
127 return self::$DOI_PLUS;