Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
bai phoi » bai choi, bai hoc, dai hoi
vien dai » hien dai
tu sach » thu sach, su sach, te sach
luoc va » nuoc va, duoc va, luc va
loc va » hoc va, luc va
vi cua » vai cua, di cua
ky va » ke va, my va, ky la

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 va) or (ly va)) bai phoi. hieu vien dai ((luoc va) OR (loc va)) hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky va) OR (ly va)) bai phoi. hieu vien dai ((luoc va) OR (loc va)) hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky va) or (ly va)) bai phoi. hieu vien dai ((luoc va) OR (loc va)) hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky va) or (ly va)) bai phoi. hieu vien dai ((luoc va) OR (loc va)) hanh vi cua vat*.