Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac hoc » cach hoc, cac hop, bac hoc
va hanh » van hanh, va danh, ban hanh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky

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

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