Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
cuu thuc » cuu tac
hanh ve » hanh vi, hanh va, hanh kem
sach ky » sac ky, sach y, sach kem
van cuu » van cau, van chu, van cu
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu van cuu thuc dan hanh ve ((cua tu) OR (cua su))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang xa hoi. hieu van cuu thuc dan hanh ve ((cua tu) or (cua su))~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu van cuu thuc dan hanh ve ((cua tu) or (cua su))*.