Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
hanh de » hanh ve, hanh kem
hanh te » hanh tu, hanh ve, hanh he
cau hoc » cau hoi, cau hoa, cao hoc
sach ty » sach y, sach tu, sach thu
van cau » van dau, van hau, van chat
nang xa » lang xa, nang ma, mang xa
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: su sach ty ((nang xa) or (nang x)) hoi. hieu van cau hoc dan ((hanh te) or (hanh de)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (nang x)) hoi. hieu van cau hoc dan ((hanh te) OR (hanh de)) cua te.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (nang x)) hoi. hieu van cau hoc dan ((hanh te) or (hanh de)) cua te*.