Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
dinh hai » dinh thai, tinh hai, dinh ha
hoc thuc » hoc huu
hac thuc » ha thuc, thach thuc, thuc thuc
va dinh » van dinh, va kinh, va tinh
tu cach » tu cac
cach tu » cach thuc
nang xa » lang xa, nang ma, mang xa
hai su » hai vu, lai su, hai so

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cach tu ((nang xa) or (nang x)) hoi. hieu van ((hac thuc) OR (hoc thuc)) va dinh hai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach tu ((nang xa) OR (nang x)) hoi. hieu van ((hac thuc) OR (hoc thuc)) va dinh hai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cach tu ((nang xa) or (nang x)) hoi. hieu van ((hac thuc) OR (hoc thuc)) va dinh hai su triet".
• Adding a wildcard symbol may retrieve word variants: tu cach tu ((nang xa) or (nang x)) hoi. hieu van ((hac thuc) OR (hoc thuc)) va dinh hai su triet*.