Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
sach ty » sach y, sach tu, xach tay
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
luc va » duc va, tuc va, loc va
va cua » va chua, via cua, ca cua
ve cam » ve cham, ve cac, va cam

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