Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va danh, ban hanh
cac hoc » cach hoc, cac hop, bac hoc
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
can ky » van ky, dan ky, ban ky
vi cua » vai cua, di cua
tu can » tu ban, tu cac, thu canh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((nang xa) OR (nang ma)) hoi. hieu va cac hoc ((va hanh) or (va thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((nang xa) OR (nang ma)) hoi. hieu va cac hoc ((va hanh) OR (va thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu can ky ((nang xa) OR (nang ma)) hoi. hieu va cac hoc ((va hanh) or (va thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu can ky ((nang xa) OR (nang ma)) hoi. hieu va cac hoc ((va hanh) or (va thanh)) vi cua tre*.