Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trinh cua » tinh cua, trinh luat, trinh quan
tong cong » trong cong, cong cong, dung cong
van toan » van tuan, van thanh, manh toan
van tan » van tuan, van ban, van tai

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 - hanh trinh cua ((nhung cong) OR (tong cong)) ((van toan) OR (van tan)) ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh trinh cua ((nhung cong) or (tong cong)) ((van toan) OR (van tan)) ban~".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh trinh cua ((nhung cong) or (tong cong)) ((van toan) OR (van tan)) ban*.