Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
danh viet » anh viet, ninh viet, nang viet
quan cau » quang cao, toan cau, quan ha
dan vien » dan viet, nhan vien, dang viet
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
truc va » thuc va, thuc vat, trung va
y lang » o lang, _ lang, tay lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y lang xa hoi. hieu quan cau truc va ((dan vien) or (danh viet)) cac tro~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y lang xa hoi. hieu quan cau truc va ((dan vien) OR (danh viet)) cac tro.
• Adding a wildcard symbol may retrieve word variants: tu sach y lang xa hoi. hieu quan cau truc va ((dan vien) or (danh viet)) cac tro*.