Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
dieu hien » dieu khien, dieu kien, bieu hien
dai thuc » dan thuc, dai thu, dai thua
vat hanh » vat thanh, van hanh, va hanh
sach tu » sach thu, cach tu, sach ty
hang ma » hang va, hang ca, tang ma
hanh va » hang va, hanh vi
ma hoi » mai hoi, xa hoi, ma hoa
va cua » va chua, via cua, ca 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 tu) OR (sach thue)) hang ma hoi. dieu hien dai thuc vat hanh va cua vat~.
• Adding a wildcard symbol may retrieve word variants: su ((sach tu) or (sach thue)) hang ma hoi. dieu hien dai thuc vat hanh va cua vat*.