Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
nhung cong » dung cong, thong cong, hang cong
hoc thien » hoc hien, hoc thieu, hoc thiet
trung va » truong va, trang va, trung ha
tran van » luan van
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap

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 hach - thanh ((trung va) or (tran van)) nhung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien hach - thanh ((trung va) OR (tran van)) nhung cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - thanh ((trung va) or (tran van)) nhung cong tac toan cau*.