Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sach thu » sach thue, sach thieu, sach tham
truc va » thuc va, thuc vat, trung va
vien da » vien dai, hien dai
sach ty » sach y, sach tu, xach tay
hang xa » hoang xa, hang va, hang ca
tuc va » thuc va, tuc xa, duc va
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) hang xa hoi. hieu vien da ((tuc va) OR (truc va)) hanh vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach thu)) hang xa hoi. hieu vien da ((tuc va) OR (truc va)) hanh vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach thu)) hang xa hoi. hieu vien da ((tuc va) OR (truc va)) hanh vi cua vat*.