Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
thuc ban » thuoc ban, thuc dan, thu ban
ban hanh » ban hang
hanh tai » thanh tai, hang tai, han tai
cau treo » cau theo, cau tren, cau triet
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
qua nam » quan nam, cua nam, quang nam
tai cau » tai cac, tai cao

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 ((nang ma) or (nang x)) hoi. hieu qua nam thuc ban hanh tai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((nang ma) OR (nang x)) hoi. hieu qua nam thuc ban hanh tai cau treo.
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((nang ma) or (nang x)) hoi. hieu qua nam thuc ban hanh tai cau treo*.