Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
nang xa » nang x, lang xa, nang ma
lang ha » long ha
qua cac » cua cac
cac hoc » cach hoc, cac hop, bac hoc
va hanh » van hanh, va thanh, va danh
te cac » tu cac, ve cac, te cao
cua tu » cua tuc, cua su, cua cu

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

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