Perhaps you should try some spelling variations:
thanh lap » thanh san, phan lap, thanh hai
sach tham » sach nha
hanh lai » hanh lam, hanh tai, thanh loi
sach thu » sach thue, sach thieu, cach thuc
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
nang xa » nang x, lang xa, nang ma
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: hoc ((sach thu) OR (sach tham)) nang xa hoi. hieu va cac duc va ((hanh lai) or (thanh lap)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach thu) OR (sach tham)) nang xa hoi. hieu va cac duc va ((hanh lai) OR (thanh lap)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach thu) OR (sach tham)) nang xa hoi. hieu va cac duc va ((hanh lai) or (thanh lap)) cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach thu) OR (sach tham)) nang xa hoi. hieu va cac duc va ((hanh lai) or (thanh lap)) cua tre*.