Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
hanh ve » hanh va, hanh kem
cac luc » cau luc, coc luc, cac nuoc
sach ky » sach y, sach ty, sach kem
nang co » nang cao, nang doc, nang noi
la tren » loai tren, dua tren, dat tren
co hoi » co hoc, co loi
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va

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) OR (sac ky)) nang co hoi. hieu vien cac luc va ((hanh ve) or (hanh vi)) la tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang co hoi. hieu vien cac luc va ((hanh ve) OR (hanh vi)) la tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang co hoi. hieu vien cac luc va ((hanh ve) or (hanh vi)) la tren*".