Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
thu sach » thuat sach, thuoc sach, thu hoach
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
tu sach » su sach, te sach, tu cach
cac luc » cau luc, coc luc, cac cuoc
nang xa » nang x, lang xa, nang ma
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: ((tu sach) or (thu sach)) ky nang xa hoi. hieu vien ((cac luc) OR (cac nuoc)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu vien ((cac luc) OR (cac nuoc)) va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang xa hoi. hieu vien ((cac luc) OR (cac nuoc)) va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang xa hoi. hieu vien ((cac luc) OR (cac nuoc)) va hanh vai cua tre*.