Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
luan nang » van nang, luan san
cong vong » cong dong, cong cong, cong nong
vong tuan » vuong tuan, cong tuan, hoang tuan
ho chieu » theo chieu, hoc thieu, mot chieu
anh tang » anh bang, anh dang, anh nang
tuan cau » toan cau, quan cau, tuan cu

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 (doi chieu)) sach - anh tang ((luan nang) OR (luan van)) cong vong tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) sach - anh tang ((luan nang) OR (luan van)) cong vong tuan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (doi chieu)) sach - anh tang ((luan nang) OR (luan van)) cong vong tuan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doi chieu)) sach - anh tang ((luan nang) OR (luan van)) cong vong tuan cau*.