Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
danh vai » danh sai, doanh van, dang van
va trien » va truyen, va thiet, va tuyen
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac duc » cac du, cao duc, cac dac
danh va » doanh va, hanh va, anh va

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