Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
va thanh » gia thanh, ban thanh, va tinh
thanh de » hanh de, thanh ve, thanh do
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cac hoc » cach hoc, cac hop, bac hoc
cuu tre » cua tre, cau tren, cau treo
tu van » tu va

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

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