Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
bach tuoc » sach duoc
sach nuoc » sach duoc, cac nuoc, dich nuoc
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, 5 hoi

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 ky nang ((x hoi) OR (x ho)). hieu viec ((bach tuoc) or (sach nuoc)) va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu viec ((bach tuoc) OR (sach nuoc)) va hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (x ho)). hieu viec ((bach tuoc) or (sach nuoc)) va hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (x ho)). hieu viec ((bach tuoc) or (sach nuoc)) va hanh lai cua tre*.