Perhaps you should try some spelling variations:
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
hang tai » hang va, dung tai
cong van » cong vang, cong san, song van
hang ca » hang va, nang cao, hang dau
van tan » van tuan, van ban, van tai
tan cau » toan cau, van cau, tan ca

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

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