Perhaps you should try some spelling variations:
nam truong » nam trong, nam trung, lam truong
truong cao » truong dai
hieu van » hieu va, thien van, lieu va
phan thi » pham thi, tran thi, phan tu
phan tai » pham tai, nhan tai, han tai
su triet » su viet, su tien, ve triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
san ky » sang ky, van ky, dan ky
te san » te ban, ke san, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te san ky ((nang xa) or (nang ma)) hoi. hieu van nam truong cao ((phan tai) OR (phan thi)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te san ky ((nang xa) OR (nang ma)) hoi. hieu van nam truong cao ((phan tai) OR (phan thi)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te san ky ((nang xa) or (nang ma)) hoi. hieu van nam truong cao ((phan tai) OR (phan thi)) su triet".
• Adding a wildcard symbol may retrieve word variants: te san ky ((nang xa) or (nang ma)) hoi. hieu van nam truong cao ((phan tai) OR (phan thi)) su triet*.