Perhaps you should try some spelling variations:
dieu cua » dieu tra
hanh dai » hanh tai, hanh dao, vanh dai
te sang » te bang, te hang, te san
sang ky » sang kyo, dang ky, tang ky
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
cac hoc » cach hoc, cac hop, bac hoc
va hanh » van hanh, va thanh, va danh
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sang ky ((nang xa) or (lang xa)) hoi. dieu cua cac hoc va hanh dai ((cua tu) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sang ky ((nang xa) OR (lang xa)) hoi. dieu cua cac hoc va hanh dai ((cua tu) OR (cua su)).
• Adding a wildcard symbol may retrieve word variants: te sang ky ((nang xa) or (lang xa)) hoi. dieu cua cac hoc va hanh dai ((cua tu) or (cua su))*.