Perhaps you should try some spelling variations:
cong trong » cong thuong, duong trong, cong trinh
trong dang » truong dang, trong dan, trong dong
doi chieu » doc hieu, doi chi, ho chieu
hanh tang » hanh trang, anh tang, hanh tung
hanh mang » nhanh mang, hanh trang, nhanh lang
dang toan » dang tran, dan toan, dung toan
tai lieu » vat lieu
toan tap » toan ban

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tai lieu) OR (doi chieu)) tinh - ((hanh tang) OR (hanh mang)) cua cong trong dang toan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tai lieu) or (doi chieu)) tinh - ((hanh tang) OR (hanh mang)) cua cong trong dang toan tap~".
• Adding a wildcard symbol may retrieve word variants: ((tai lieu) or (doi chieu)) tinh - ((hanh tang) OR (hanh mang)) cua cong trong dang toan tap*.