Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
cau tren » cu tren, dau tren, ca tren
nam thuc » am thuc, nam thu, nam tu
hanh vai » hanh vi, hanh va, hanh tai
vat hanh » vat thanh, van hanh, va hanh
vai cau » va cau, van cau, vai cac
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((nang ma) or (nang x)) hoi. hieu ve ((nam thuc) OR (nam thuoc)) vat hanh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang ma) OR (nang x)) hoi. hieu ve ((nam thuc) OR (nam thuoc)) vat hanh vai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((nang ma) or (nang x)) hoi. hieu ve ((nam thuc) OR (nam thuoc)) vat hanh vai cau tren".
• Adding a wildcard symbol may retrieve word variants: te sach y ((nang ma) or (nang x)) hoi. hieu ve ((nam thuc) OR (nam thuoc)) vat hanh vai cau tren*.