Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
van cuu » van cau, van chu, van cu
hanh ve » hanh vi, hanh va
cuu hoc » cua hoc, cuu thuoc, cuu khoa
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
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: tu sach ky ((nang xa) or (dang xay)) hoi. hieu van cuu hoc dan ((hanh ve) or (hanh kem)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (dang xay)) hoi. hieu van cuu hoc dan ((hanh ve) OR (hanh kem)) cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (dang xay)) hoi. hieu van cuu hoc dan ((hanh ve) or (hanh kem)) cua te*.