Perhaps you should try some spelling variations:
sach tham » sach nha
dan thanh » dang thanh, danh thanh, ban thanh
hieu van » hieu va, thien van, lieu va
thanh de » hanh de, thanh ve, thanh do
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
nang xa » lang xa, nang ma, mang xa
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tham ((nang xa) OR (nang x)) hoi. hieu van nam thuc dan thanh de ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tham ((nang xa) OR (nang x)) hoi. hieu van nam thuc dan thanh de ((cua te) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach tham ((nang xa) OR (nang x)) hoi. hieu van nam thuc dan thanh de ((cua te) or (cua tu))*".