PowerPoint อักษรนำ
http://elsd.ssru.ac.th/arun_su/pluginfile.php/65/mod_page/content/1/%E0%B8%AD%E0%B8%B1%E0%B8%81%E0%B8%A9%E0%B8%A3%E0%B8%99%E0%B8%B3.pptx