Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thuc day » thuc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
cua viet » ca viet, hoa viet, cua vat
qua nam » quan nam, cua nam, quang nam
sach ty » sach y, sach tu, sach thu
nang xa » lang xa, nang ma, mang xa
danh di » danh du, xanh di, danh dien
hanh ve » hanh vi, hanh va, hanh kem

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ty ((nang xa) or (nang x)) hoi. hieu qua nam thuc day ((danh di) or (hanh ve)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty ((nang xa) OR (nang x)) hoi. hieu qua nam thuc day ((danh di) OR (hanh ve)) cua viet.
• Adding a wildcard symbol may retrieve word variants: hoc sach ty ((nang xa) or (nang x)) hoi. hieu qua nam thuc day ((danh di) or (hanh ve)) cua viet*.