Perhaps you should try some spelling variations:
cuu thuc » cuu tac
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
hanh de » hanh ve, hanh kem
hanh te » hanh tu, hanh ve, hanh he
van cuu » van cau, van chu, van cu
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
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 ty) OR (sach thu)) nang xa hoi. hieu van cuu thuc dan ((hanh te) or (hanh de)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sach thu)) nang xa hoi. hieu van cuu thuc dan ((hanh te) OR (hanh de)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) OR (sach thu)) nang xa hoi. hieu van cuu thuc dan ((hanh te) or (hanh de)) cua te".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) OR (sach thu)) nang xa hoi. hieu van cuu thuc dan ((hanh te) or (hanh de)) cua te*.