Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
chiet tach » chieu sach
nhung cong » dung cong, thong cong, hang cong
cong ngang » cong nhan, cong quang, cong lang
ngang tan » nganh toan, nang tai, nang tao
hang ca » nang cao, hang tai, hang dau
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 (chiet tach)) - thanh ((hang ca) OR (hang va)) nhung cong ngang tan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (chiet tach)) - thanh ((hang ca) OR (hang va)) nhung cong ngang tan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (chiet tach)) - thanh ((hang ca) OR (hang va)) nhung cong ngang tan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (chiet tach)) - thanh ((hang ca) OR (hang va)) nhung cong ngang tan cau*.