Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
sach thu » sach thieu, sach tham, cach thuc
hieu van » hieu va, thien van, lieu va
cau thuc » cau truc, cuu thuc, can thuc
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
thuc va » thuc vat, thuc dan, thuc day
dau hai » dai hai, dau ha, cau hai
hai cua » thai cua, dai cua, hoi cua
va dau » va dao
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach thu) or (sach thue)) nang xa hoi. hieu van cau thuc va dau hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach thu) OR (sach thue)) nang xa hoi. hieu van cau thuc va dau hai cua te.
• Adding a wildcard symbol may retrieve word variants: thu ((sach thu) or (sach thue)) nang xa hoi. hieu van cau thuc va dau hai cua te*.