Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sach thu » sach thue, sach thieu, sach tham
tang mai » tang ma, tang tai, lang mai
dam thuc » am thuc, dan thuc, nam thuc
vat hanh » vat thanh, van hanh, va hanh
sach ty » sach y, sach tu, xach tay
mai hoi » mai khoi, dai hoi, lai hoi
da thuc » dan thuc, dai thuc, day thuc
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)) tang mai hoi. hieu vien ((da thuc) OR (dam thuc)) vat hanh vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach thu)) tang mai hoi. hieu vien ((da thuc) OR (dam thuc)) vat hanh vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach thu)) tang mai hoi. hieu vien ((da thuc) OR (dam thuc)) vat hanh vi cua vat*.