Không rõ. (2001). Product Planning and Development. Youth PublishingHouse.
Trích dẫn kiểu ChicagoKhông rõ. Product Planning and Development. Youth PublishingHouse, 2001.
MLA引文Không rõ. Product Planning and Development. Youth PublishingHouse, 2001.
警告:這些引文格式不一定是100%准確.