Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nang mai » nang tai, lang mai, nang cai
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
van dam » van nam, van dao, van dau
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, dua tren
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky
dam tu » nam tu, cam tu, tam tu

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 mai) OR (nang ma)) hoi. hieu van dam tu va hanh vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky ((nang mai) OR (nang ma)) hoi. hieu van dam tu va hanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky ((nang mai) OR (nang ma)) hoi. hieu van dam tu va hanh vi ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu san ky ((nang mai) OR (nang ma)) hoi. hieu van dam tu va hanh vi ((cua tre) or (cua triet))*.