Perhaps you should try some spelling variations:
thuoc sai » thuoc tai, thuoc san, thuoc sach
van tuan » van quan, van ban, anh tuan
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
duc van » duc va, duc tan, duc manh
sai ky » sac ky
ve cam » ve cham, ve cac, va cam
vai va » mai va, hai va, lai va
dai va » mai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sai ky mang may hoi. hieu ve cam duc van tuan ((vai va) or (dai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sai ky mang may hoi. hieu ve cam duc van tuan ((vai va) OR (dai va)) triet.
• Adding a wildcard symbol may retrieve word variants: thuoc sai ky mang may hoi. hieu ve cam duc van tuan ((vai va) or (dai va)) triet*.