Perhaps you should try some spelling variations:
thieu nien » thien nhien
hieu vien » hieu hien, hieu viec, hieu tieng
dac khoa » dai khoa, dau khoa, cac khoan
danh day » danh dau, dan day, doanh dao
cua tre » cua te, cuu tre, cua triet
day cua » dai cua
va danh » va dinh, va dan, va hanh
cac luc » cau luc, coc luc, cac nuoc
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
so sac » so sach, so dac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sac ky nang ((dac khoa) OR (da khoa)). ((hieu vien) or (thieu nien)) cac luc va danh day cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sac ky nang ((dac khoa) OR (da khoa)). ((hieu vien) OR (thieu nien)) cac luc va danh day cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky nang ((dac khoa) OR (da khoa)). ((hieu vien) or (thieu nien)) cac luc va danh day cua tre".
• Adding a wildcard symbol may retrieve word variants: so sac ky nang ((dac khoa) OR (da khoa)). ((hieu vien) or (thieu nien)) cac luc va danh day cua tre*.