Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sach thue » sach thu, sach thieu, sach tham
xach tay » canh tay
dang xay » dang van, van xay
hanh va » hang va, hanh vi
vien da » vien dai, hien dai
xay hoi » xa hoi, tay hoi, cay phoi
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((xach tay) or (sach thue)) dang xay hoi. hieu vien da ((xuc va) or (thuc vat)) hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((xach tay) OR (sach thue)) dang xay hoi. hieu vien da ((xuc va) OR (thuc vat)) hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((xach tay) or (sach thue)) dang xay hoi. hieu vien da ((xuc va) or (thuc vat)) hanh va cua tre*.