Perhaps you should try some spelling variations:
nang dau » hang dau, xang dau, nang du
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach ty, sach kem
dau hoi » cau hoi, dai hoi, dan hoi
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa

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 ky) or (sach y)) nang dau hoi. hieu va cam tuc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang dau hoi. hieu va cam tuc va hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) nang dau hoi. hieu va cam tuc va hanh vai cua tre*.