Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vat danh » va danh, van danh, luat danh
danh vai » danh sai, danh va, doanh van
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
vai cau » va cau, van cau, vai cac
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 y ((nang ma) or (nang x)) hoi. hieu va nam thuc vat danh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang ma) OR (nang x)) hoi. hieu va nam thuc vat danh vai cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) or (nang x)) hoi. hieu va nam thuc vat danh vai cau tren*.