Perhaps you should try some spelling variations:
sach tham » sach nha
hanh vai » hanh vi, hanh va, hanh 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
lang hoa » hang hoa, lang ha, nang hoa
hieu van » hieu va, thien van, lieu va
hoa hoi » khoa hoi, hoa hoc, hoa doi
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
su tien » su kien, su hien, tu tieng
vai su » va su, van su, lai su

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 tham)) lang hoa hoi. hieu van nam thuc van hanh vai su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((((sach ky) OR (sach ty))) OR (sach tham)) lang hoa hoi. hieu van nam thuc van hanh vai su tien.
• Adding a wildcard symbol may retrieve word variants: tu ((((sach ky) or (sach ty))) or (sach tham)) lang hoa hoi. hieu van nam thuc van hanh vai su tien*.