Perhaps you should try some spelling variations:
sach thu » sach thue, sach tham, cach thuc
hieu van » hieu va, thien van, lieu va
hanh dao » thanh dat, thanh dam, doanh dao
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
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: tu ((sach thu) OR (sach thieu)) lang xa hoi. hieu van cam tuc xa ((hanh dao) or (lanh dao)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach thu) OR (sach thieu)) lang xa hoi. hieu van cam tuc xa ((hanh dao) OR (lanh dao)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach thu) OR (sach thieu)) lang xa hoi. hieu van cam tuc xa ((hanh dao) or (lanh dao)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach thu) OR (sach thieu)) lang xa hoi. hieu van cam tuc xa ((hanh dao) or (lanh dao)) cua tre*.