Perhaps you should try some spelling variations:
van thiet » dan thiet, can thiet, van thien
truc va » thuc va, thuc vat, trung va
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
tu sac » tu sach, tu cac, tu san
xuc va » duc va, tuc va, luc va
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa

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: tu sac ky sang ma hoi. hieu ve chat ((xuc va) OR (truc va)) hanh vi ((van thiet) OR (va thiet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky sang ma hoi. hieu ve chat ((xuc va) or (truc va)) hanh vi ((van thiet) OR (va thiet))~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky sang ma hoi. hieu ve chat ((xuc va) or (truc va)) hanh vi ((van thiet) OR (va thiet))*.