Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu quang » thieu quang, hieu quan, hieu qua
canh trinh » canh tranh, hanh trinh, canh tinh
trinh han » trinh quan
trong van » trong cac
han vung » han ung, dan vung, ban vung
dang van » hoang van, hang va
van cau » van dau, van hau, 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: doi ((chieu sach) or (hieu quang)) - canh trinh han vung ((dang van) or (trong van)) van cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (hieu quang)) - canh trinh han vung ((dang van) OR (trong van)) van cau.
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (hieu quang)) - canh trinh han vung ((dang van) or (trong van)) van cau*.