Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
chieu sach » chinh sach, chiet tach, chieu sang
hieu sach » hieu cach, dien sach, hieu cac
tranh cua » doanh cua, manh cua
hoang van » hang va
duong van » duong va, luong va, dang van
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sach) OR (chieu sach)) - hanh tranh cua cong ((hoang van) or (duong van)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (chieu sach)) - hanh tranh cua cong ((hoang van) OR (duong van)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) OR (chieu sach)) - hanh tranh cua cong ((hoang van) or (duong van)) toan cao".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) OR (chieu sach)) - hanh tranh cua cong ((hoang van) or (duong van)) toan cao*.