Perhaps you should try some spelling variations:
danh viet » anh viet, ninh viet, nang viet
danh vien » doanh vien, dan vien, danh kien
truc va » thuc va, thuc vat, trung va
ca truc » cau truc, ca tru, ba truc
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky lang » ky nang, ky dang, ky tang
ha hoi » ha noi, xa hoi, va hoi
qua ca » qua cac, qua cua, qua cai

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 ky lang ((ha hoi) OR (hoa hoi)). hieu qua ca truc va ((danh vien) or (danh viet)) cac tro~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((ha hoi) OR (hoa hoi)). hieu qua ca truc va ((danh vien) OR (danh viet)) cac tro.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((ha hoi) OR (hoa hoi)). hieu qua ca truc va ((danh vien) or (danh viet)) cac tro".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ((ha hoi) OR (hoa hoi)). hieu qua ca truc va ((danh vien) or (danh viet)) cac tro*.