Perhaps you should try some spelling variations:
thuoc van » thuoc va, thuc van, thuoc ban
cau tren » cu tren, dau tren, ca tren
hanh vai » hanh vi, hanh va, hanh tai
dang xay » dang van, van xay
van hanh » van thanh, ban hanh, van anh
nang ma » tang ma, sang ma, nang cao
vai cau » va cau, van cau, vai cac
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
le ta » le tai, le va
le na » le nam, le va, le ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((nang ma) or (dang xay)) hoi. hieu ((le na) OR (le ta)) thuoc van hanh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((nang ma) OR (dang xay)) hoi. hieu ((le na) OR (le ta)) thuoc van hanh vai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((nang ma) or (dang xay)) hoi. hieu ((le na) OR (le ta)) thuoc van hanh vai cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang ma) or (dang xay)) hoi. hieu ((le na) OR (le ta)) thuoc van hanh vai cau tren*.