Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, ho chieu
hoc thieu » toc thieu, hoc hien
tang luan » dung luan
luan phan » luan van, luan hoan
phan cong » thanh cong
anh tang » anh bang, anh dang, anh nang
cong tan » cong tac, cong san, cong thanh
tran cau » tran chau, ran cau, tra cau
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: ((doi chieu) or (hoc thieu)) sach - anh tang luan phan cong tan ((tran cau) OR (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (hoc thieu)) sach - anh tang luan phan cong tan ((tran cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (hoc thieu)) sach - anh tang luan phan cong tan ((tran cau) OR (toan cau))".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (hoc thieu)) sach - anh tang luan phan cong tan ((tran cau) OR (toan cau))*.