Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh tai, hanh van
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
xang ma » tang ma, nang ma, sang ma
van cau » van dau, van hau, van chat
duc van » duc va, duc manh, duc phan
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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 xang ma hoi. hieu van cau ((duc van) or (duc tan)) ((hanh vai) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang ma hoi. hieu van cau ((duc van) OR (duc tan)) ((hanh vai) OR (hanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty xang ma hoi. hieu van cau ((duc van) or (duc tan)) ((hanh vai) or (hanh va)) cua tre*.