Perhaps you should try some spelling variations:
thien van » thi van
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
hieu van » lieu va, hieu ve
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, luc va
ma hoi » mai hoi, xa hoi, ma hoa
so sac » so sach, so dac

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

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