แหล่งที่มา https://sites.google.com/view/krupreechaonline/%E0%B8%84%E0%B8%AD%E0%B8%A1-%E0%B8%A1-5/%E0%B8%A3%E0%B8%B2%E0%B8%A2%E0%B8%A7%E0%B8%8A%E0%B8%B2-sketch-up

https://occupationandtechnologym3.wordpress.com/1-7-%E0%B8%A1%E0%B8%B8%E0%B8%A1%E0%B8%A1%E0%B8%AD%E0%B8%87%E0%B8%95%E0%B9%88%E0%B8%B2%E0%B8%87%E0%B9%86-%E0%B9%83%E0%B8%99-google-sketchup-8/