Perhaps you should try some spelling variations:
dinh cuu » dinh chi
tham hoc » thai hoc, tham hoa, than hoc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
va tham » van tham, va cham, va thanh
tang ma » mang may, tang van
tang xa » trang xa, lang xa, tang ha
sac ky » cac ky, sai ky
vi cuu » vi luu, vinh cuu
te sac » te sach, te cac, te 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 sac ky ((tang xa) OR (tang ma)) hoi. hieu va tham hoc va hanh ((vi cuu) or (dinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((tang xa) OR (tang ma)) hoi. hieu va tham hoc va hanh ((vi cuu) OR (dinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((tang xa) OR (tang ma)) hoi. hieu va tham hoc va hanh ((vi cuu) or (dinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((tang xa) OR (tang ma)) hoi. hieu va tham hoc va hanh ((vi cuu) or (dinh cuu)) tre*.