Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
thai cua » than cua, tai cuc, tri cua
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
tai cua » tai cuc, tri cua, dai cua
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
ve nam » he nam, va nam, le nam

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