Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
su tien » su kien, su hien, tu tieng
sach ky » sac ky, sach y, sach kem
lang ha » long ha
sach ty » sach y, sach tu, xach tay
tai su » tai so, tai tu, lai su
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((((sach ky) or (sach ty))) or (sach thu)) lang ha hoi. hieu van nam thuc van hanh tai su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((((sach ky) OR (sach ty))) OR (sach thu)) lang ha hoi. hieu van nam thuc van hanh tai su tien.
• Adding a wildcard symbol may retrieve word variants: tu ((((sach ky) or (sach ty))) or (sach thu)) lang ha hoi. hieu van nam thuc van hanh tai su tien*.