Perhaps you should try some spelling variations:
cua thuoc » nha thuoc, cay thuoc, cua nuoc
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
lang ha » long ha
ky lang » ky nang, ky dang, ky tang
duc ban » duc tan, dua ban, duc man
duc van » duc va, duc tan, duc manh
tai cua » thai cua, tai cuc, tri cua
su xac » pu xac, su cac
su sac » su sach, su cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) or (su xac)) ky lang ha noi. hieu van cham ((duc ban) OR (duc van)) thanh tai cua thuoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su xac)) ky lang ha noi. hieu van cham ((duc ban) OR (duc van)) thanh tai cua thuoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) or (su xac)) ky lang ha noi. hieu van cham ((duc ban) OR (duc van)) thanh tai cua thuoc".
• Adding a wildcard symbol may retrieve word variants: ((su sac) or (su xac)) ky lang ha noi. hieu van cham ((duc ban) OR (duc van)) thanh tai cua thuoc*.