Perhaps you should try some spelling variations:
doanh vien » doanh tien, doanh chien, thanh vien
vien cac » vien bach, vien dai, vien da
thuc va » thuc vat, thuc dan, thuc day
truc va » thuc vat, trung va
tu sach » thu sach, te sach, tu cach
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
su sach » so sach, vu sach
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) OR (su sach)) ky tang xa hoi. hieu qua ca ((truc va) or (thuc va)) doanh vien cac tro~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky tang xa hoi. hieu qua ca ((truc va) OR (thuc va)) doanh vien cac tro.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky tang xa hoi. hieu qua ca ((truc va) or (thuc va)) doanh vien cac tro".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky tang xa hoi. hieu qua ca ((truc va) or (thuc va)) doanh vien cac tro*.