Perhaps you should try some spelling variations:
thien van » thi van
doanh van » doan van, doanh va, doanh ban
danh vai » danh sai, danh va, dang van
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
nam tu » nam thu, nam thuc
hoa » khoa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang xa hoi. ((hieu ve) or (thien van)) nam tu va ((danh vai) OR (doanh van)) hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. ((hieu ve) OR (thien van)) nam tu va ((danh vai) OR (doanh van)) hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. ((hieu ve) or (thien van)) nam tu va ((danh vai) OR (doanh van)) hoa viet".
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. ((hieu ve) or (thien van)) nam tu va ((danh vai) OR (doanh van)) hoa viet*.