Perhaps you should try some spelling variations:
hieu vien » hieu viec, thieu nien, hieu tieng
hieu hien » bieu hien, dieu hien, chieu chien
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
cac lo » cac lop, cac co, cac bo
va cua » va chua, via cua, ca cua
lo va » lo van, lao va, ly va

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 nang xa hoi. ((hieu vien) OR (hieu hien)) cac lo va hanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. ((hieu vien) OR (hieu hien)) cac lo va hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu vien) OR (hieu hien)) cac lo va hanh va cua tre*.