Perhaps you should try some spelling variations:
thien van » thi van
thuat sai » thuat bai, thuat san, thuat cai
hieu van » hieu va, lieu va, hieu ve
van hanh » van thanh, ban hanh, van anh
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
cau dat » cai dat, cau hat, chap dat
dat van » dao van, dat va, dam van
sai ky » sac ky
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sai ky tang ma hoi. ((hieu van) or (thien van)) cau dat van hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sai ky tang ma hoi. ((hieu van) OR (thien van)) cau dat van hanh vi cua vat.
• Adding a wildcard symbol may retrieve word variants: thuat sai ky tang ma hoi. ((hieu van) or (thien van)) cau dat van hanh vi cua vat*.