Perhaps you should try some spelling variations:
danh vai » danh sai, doanh van, dang van
tu sach » thu sach, su sach, tu cach
danh va » doanh va, hanh va, anh va
va giao » van giao, va giai, va gia
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ly lang » ly hang, ly vang, le lang
te sach » toc sach
cuu tre » cua tre, cau tren, cau treo

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