Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach
thuat tach » thuat sach, thuat mach, thuat tac
dung huong » dung thuong, dung phuong, dong huong
hanh tram » hanh tam, hanh trang, thanh tran
tram xay » tra xay, pham xay, thau xay
than cau » toan cau, than cap, thanh chau
phan cau » phan dau, phan cac, phan tu

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: hoc ((thiet tach) OR (thuat tach)) - hanh tram xay dung huong dan ((than cau) OR (phan cau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet tach) OR (thuat tach)) - hanh tram xay dung huong dan ((than cau) or (phan cau))~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) OR (thuat tach)) - hanh tram xay dung huong dan ((than cau) or (phan cau))*.