Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sach thu » sach thue, sach thieu, sach tham
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, xach tay
hang ma » hang va, hang ca, tang ma
vien da » vien dai, hien dai
da thuc » dan thuc, dai thuc, dam thuc
ma hoi » mai hoi, xa hoi, ma hoa
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 ma hoi. hieu vien da thuc van hanh vi cua vat~.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach thu)) hang ma hoi. hieu vien da thuc van hanh vi cua vat*.