Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
toan thiet » hoan thien, luan thiet, toan tien
nhung cong » dung cong, thong cong, hang cong
hoc thien » hoc hien, hoc thieu, hoc thiet
toan hoat » toan khoa, toan hoc, toan ho
cong tan » cong tac, cong san, cong thanh
tan khan » tan khang, tan nhan, toan khoan
khan cap » khan ap, than cap, khoan cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thien thanh - tinh ((toan hoat) or (toan thiet)) nhung cong tan khan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien thanh - tinh ((toan hoat) OR (toan thiet)) nhung cong tan khan cap.
• Adding a wildcard symbol may retrieve word variants: hoc thien thanh - tinh ((toan hoat) or (toan thiet)) nhung cong tan khan cap*.