Perhaps you should try some spelling variations:
ban hanh » ban hang
hanh dai » hanh tai, hanh dao, vanh dai
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
long ha » dong ha, cong ha, dong hoa
qua cac » cua cac
cac hoc » cach hoc, cac hop, bac hoc
hoc ban » hoc bang, hoc dan, hoc bai
cua te » cua tu

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

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