Perhaps you should try some spelling variations:
van thanh » ban thanh
nam thuc » nam thuoc, am thuc, nam thu
van tuan » van quan, van ban, anh tuan
tu sach » thu sach, su sach, te sach
tai cuu » tai cuc, tai buu, tai cua
cuu tre » cua tre, cau tren, cau treo
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
va nam » van nam, ha nam, va nay

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