Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach, vu sach
vai cua » dai cua, hai cua, lai cua
thuc va » thuc vat, thuc dan, thuc day
vu cham » va cham, vu kham, tu cham
sach ky » sac ky, sach y, sach ty
hieu vu » hieu va, hieu ve, hieu su
dai hoi » dai hoc, dai hai, dai moi
cai hoi » cau hoi, cai hoa, lai hoi
cua tre » cua te, cuu tre, cua triet
tuc va » truc va, tuc xa, duc va

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 nang ((cai hoi) OR (dai hoi)). hieu vu cham ((tuc va) or (thuc va)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((cai hoi) OR (dai hoi)). hieu vu cham ((tuc va) OR (thuc va)) hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((cai hoi) OR (dai hoi)). hieu vu cham ((tuc va) or (thuc va)) hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((cai hoi) OR (dai hoi)). hieu vu cham ((tuc va) or (thuc va)) hanh vai cua tre*.