Perhaps you should try some spelling variations:
khau sach » hau sach, pham sach, ham sach
khoa sach » hoc sach
hanh tang » hanh trang, anh tang, hanh mang
tang luan » dung luan
luan nang » luan van, van nang, luan san
nang cong » nang song, dang cong, bang cong
cau sach » cao sach, hau sach, rau sach
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((cau sach) OR (((khau sach) OR (khoa sach)))) - hanh tang luan nang cong dan toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((cau sach) or (((khau sach) OR (khoa sach)))) - hanh tang luan nang cong dan toan ban~".
• Adding a wildcard symbol may retrieve word variants: theo ((cau sach) or (((khau sach) OR (khoa sach)))) - hanh tang luan nang cong dan toan ban*.