Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
chat tuc » chat xuc, luat tuc, chat huu
sach tai » sach bai, sach tham, sach dao
danh vai » danh sai, danh va, dang van
ve chat » va chat, van chat
sach ta » sach xa, sach ha, sach va
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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 ta) OR (sach tai)) tang xa hoi. hieu ve chat tuc va ((danh vai) or (doanh van)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ta) OR (sach tai)) tang xa hoi. hieu ve chat tuc va ((danh vai) OR (doanh van)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ta) OR (sach tai)) tang xa hoi. hieu ve chat tuc va ((danh vai) or (doanh van)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ta) OR (sach tai)) tang xa hoi. hieu ve chat tuc va ((danh vai) or (doanh van)) cua tre*.