Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
chat xuc » chat huu, cam xuc, chao xu
sach ty » sach y, sach tu, sach thu
va hanh » va thanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
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 ty nang ma hoi. ((hieu ve) OR (hieu van)) chat xuc ((va hanh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ma hoi. ((hieu ve) OR (hieu van)) chat xuc ((va hanh) OR (van hanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ma hoi. ((hieu ve) OR (hieu van)) chat xuc ((va hanh) or (van hanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ma hoi. ((hieu ve) OR (hieu van)) chat xuc ((va hanh) or (van hanh)) vi cua tre*.