Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nang ma » sang ma, nang cao, mang may
danh vi » hanh vi, dinh vi, danh di
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
luc va » duc va, tuc va, loc va
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
vi su » va su, ve su, ki su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang ma) OR (tang ma)) hoi. hieu va cam ((luc va) OR (hoc va)) danh vi su triet~.
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang ma) or (tang ma)) hoi. hieu va cam ((luc va) or (hoc va)) danh vi su triet*.