http://www.lytuongnguoiviet.com/index.php?option=com_content&view=article&id=9011:bai-hc-u-tien&catid=56:binh-lun&Itemid=111

http://nguoivietnamoi.blogspot.com/2011/08/chu-au-tu-nha-thu-nhap-thap-giai-trinh.html