Perhaps you should try some spelling variations:
chieu sach » chiet tach, chieu sang, chieu xanh
nhung cong » dung cong, thong cong, hang cong
trinh ven » trinh van, trinh den, tinh ven
cong lang » cong vang, cong luong, cong quang
lang toan » dang toan, lang thang, lang thanh
trinh ve » trinh he, trinh va, trinh vi
toan ban » van ban

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

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