Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
ly vang » ly van, ly quang
ly hang » ly quang
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
va cua » va chua, via cua, ca cua

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 ((ly vang) or (ly hang)) xa hoi. hieu va cam ((duc van) or (duc anh)) hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ly vang) OR (ly hang)) xa hoi. hieu va cam ((duc van) OR (duc anh)) hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ly vang) or (ly hang)) xa hoi. hieu va cam ((duc van) or (duc anh)) hanh va cua tre*.