Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
hieu cach » hieu cac, chieu sach, hieu ca
tranh cua » doanh cua, manh cua
dung cong » dung trong
cua dung » cua dang, cua dong, qua dung
dan toan » van toan, dan than, manh toan
dan chan » dan gian, dan ca, van chat

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 (hieu cach)) - canh tranh cua dung cong ((dan toan) or (dan chan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - canh tranh cua dung cong ((dan toan) OR (dan chan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu cach)) - canh tranh cua dung cong ((dan toan) or (dan chan)) cao*.