Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh tai, hanh van
hanh va » hang va, hanh vi
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
mau hoi » cau hoi, mai hoi, mau ho
ky danh » ky anh
ky dang » ky nang
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: thu sach ((ky dang) or (ky danh)) mau hoi. hieu van cam duc va ((hanh vai) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky dang) OR (ky danh)) mau hoi. hieu van cam duc va ((hanh vai) OR (hanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky dang) or (ky danh)) mau hoi. hieu van cam duc va ((hanh vai) or (hanh va)) cua tre*.