Ex4. Post link of these 2 books in your blog

1.https://books.google.co.th/books?id=KxXSxtYdSkEC&pg=PR1&hl=th&source=gbs_selected_pages&cad=3#v=onepage&q&f=false
2.https://www.elsevier.com/books/materials-selection-in-mechanical-design/ashby/978-0-08-046864-8
3.http://jpkc.fudan.edu.cn/picture/article/255/1c/8c/8a256ed84a98beafbd225ea6936e/43f6d2e4-9479-4872-9970-f70754fce954.pdf