Perhaps you should try some spelling variations:
luoc van » luoc can, luoc va, luc van
van hanh » van thanh, ban hanh, van anh
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
luu tre » cuu tre, luy tre
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
tru » truc

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky sang ma hoi. hieu ((ke khai) or (va khao)) luoc van hanh vi ((luu tre) OR (luu tru))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky sang ma hoi. hieu ((ke khai) OR (va khao)) luoc van hanh vi ((luu tre) OR (luu tru)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky sang ma hoi. hieu ((ke khai) or (va khao)) luoc van hanh vi ((luu tre) OR (luu tru))".
• Adding a wildcard symbol may retrieve word variants: te sac ky sang ma hoi. hieu ((ke khai) or (va khao)) luoc van hanh vi ((luu tre) OR (luu tru))*.