Perhaps you should try some spelling variations:
hieu cac » hieu luc, hieu va, hieu van
van hanh » van thanh, ban hanh, van anh
chat xuc » chat huu, cam xuc, chao xu
hieu cao » chieu cao, hieu ca, kieu cao
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
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: tu sach ky tang ma hoi. ((hieu cao) OR (hieu cac)) chat xuc ((va danh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ma hoi. ((hieu cao) OR (hieu cac)) chat xuc ((va danh) OR (van hanh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang ma hoi. ((hieu cao) OR (hieu cac)) chat xuc ((va danh) or (van hanh)) vi cua tre*".