Perhaps you should try some spelling variations:
danh vien » doanh vien, danh viet, danh kien
thu sach » tu sach, thuat sach, thuoc sach
dan vien » dan viet, nhan vien, danh viet
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
qua cau » quan cau, qua cac, qua ca
truc va » thuc va, trung va

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