Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
lang mai » lang dai, lang hai, lang man
sach thu » sach thue, sach thieu, sach tham
cau luc » cau truc, cau phuc
cam luc » cam xuc
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
sach tu » cach tu, sach ty, sach uu
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 tu)) lang mai hoi. hieu ve ((cam luc) or (cau luc)) gia thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach thu) OR (sach tu)) lang mai hoi. hieu ve ((cam luc) OR (cau luc)) gia thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach thu) or (sach tu)) lang mai hoi. hieu ve ((cam luc) or (cau luc)) gia thanh dai cua tre*.