Perhaps you should try some spelling variations:
danh vien » doanh vien, danh viet, dan vien
thu sach » tu sach, thuat sach, thuoc sach
dang xay » dang van, van xay
vien cac » vien bach, vien dai, vien da
sach ky » sac ky, sach y, sach ty
truc va » thuc va, trung va
lang xa » lang ha, lang van
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: thu sach ky ((lang xa) or (dang xay)) hoi. hieu qua ca ((truc va) OR (thuc vat)) danh vien cac tro~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((lang xa) OR (dang xay)) hoi. hieu qua ca ((truc va) OR (thuc vat)) danh vien cac tro.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((lang xa) or (dang xay)) hoi. hieu qua ca ((truc va) OR (thuc vat)) danh vien cac tro".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((lang xa) or (dang xay)) hoi. hieu qua ca ((truc va) OR (thuc vat)) danh vien cac tro*.