Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
hanh hang » thanh hang, hang hang, hanh han
ho chieu » theo chieu, doi chieu, mot chieu
va tuong » va thong, xa truong, va phuong
cong tac » cong ty
tac tran » tan tran, tac trai, tac tren
tran cau » tran chau, toan cau, ran cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) or (hoc thieu)) tinh - hanh hang ((va tuong) OR (va thuong)) cong tac tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) tinh - hanh hang ((va tuong) OR (va thuong)) cong tac tran cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) tinh - hanh hang ((va tuong) OR (va thuong)) cong tac tran cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) tinh - hanh hang ((va tuong) OR (va thuong)) cong tac tran cau*.