Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hoc thien » hoc hien, hoc thieu, hoc thiet
tran tuan » tran xuan, tran quang, tran thanh
doanh cua » doanh luan
nhung don » nhung van, nhung bo
dung cong » dung trong
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 - hanh ((tran tuan) or (doanh cua)) ((nhung don) or (dung cong)) tinh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien hach - hanh ((tran tuan) OR (doanh cua)) ((nhung don) OR (dung cong)) tinh toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - hanh ((tran tuan) or (doanh cua)) ((nhung don) or (dung cong)) tinh toan cau*.