Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach tham
thanh va » thanh van, hanh va, thanh ha
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
hang xa » hoang xa, hang va, hang ca
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
va cua » va chua, via cua, ca cua

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 thi) OR (sach thieu)) hang xa hoi. hieu va tham ((xuc va) or (tuc va)) thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach thi) OR (sach thieu)) hang xa hoi. hieu va tham ((xuc va) OR (tuc va)) thanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach thi) OR (sach thieu)) hang xa hoi. hieu va tham ((xuc va) or (tuc va)) thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach thi) OR (sach thieu)) hang xa hoi. hieu va tham ((xuc va) or (tuc va)) thanh va cua tre*.