Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
thu sach » thuat sach, thuoc sach, thu hoach
hanh ve » hanh va, hanh kem
dai luc » dai luoc, dai luan, dai thuc
tu sach » su sach, te sach, tu cach
nang co » nang cao, nang doc, nang noi
ca tren » cau tren, cu tren, la tren
co hoi » co hoc, co loi
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) OR (thu sach)) ky nang co hoi. hieu vien dai luc va ((hanh ve) or (hanh vi)) ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang co hoi. hieu vien dai luc va ((hanh ve) OR (hanh vi)) ca tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang co hoi. hieu vien dai luc va ((hanh ve) or (hanh vi)) ca tren*".