Perhaps you should try some spelling variations:
danh gia » dan gian
van danh » van doanh, van anh, van hanh
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
co viet » so viet, o viet, hoc viet
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, 5 hoi

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 nang ((x hoi) OR (x ho)). hieu ve cac duc van danh gia ((cua viet) or (co viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu ve cac duc van danh gia ((cua viet) OR (co viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (x ho)). hieu ve cac duc van danh gia ((cua viet) or (co viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (x ho)). hieu ve cac duc van danh gia ((cua viet) or (co viet))*.