ส่งงานสืบค้น E-Book ค่ะ

http://mis.science.cmu.ac.th/web51/scinews/files/%E0%B8%89%E0%B8%9A%E0%B8%B1%E0%B8%9A%E0%B9%80%E0%B8%95%E0%B9%87%E0%B8%A1.pdf

http://www.elkalube.com/index.php/elkalube-oil?gclid=CMeL1a-I0aMCFQFB6wodg2g2tg

http://www.energygreenhealth.com/8956363737/p28-29.pdf