Perhaps you should try some spelling variations:
thien van » thi van
doanh va » doan va, doanh tai, doanh cua
su sach » so sach, vu sach
vu khac » vu kham, vu khanh, bui khac
cao hoi » cau hoi, co hoi, cao hoc
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
danh va » hanh va, anh va, dan va
cua tre » cua te, cuu tre, cua triet

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) or (vu khac)) ky nang cao hoi. thien van cau truc va ((danh va) OR (doanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu khac)) ky nang cao hoi. thien van cau truc va ((danh va) OR (doanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu khac)) ky nang cao hoi. thien van cau truc va ((danh va) OR (doanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu khac)) ky nang cao hoi. thien van cau truc va ((danh va) OR (doanh va)) cua tre*.