Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
nam xua » nam cua, nam mua, nam qua
xua ban » xuat ban, cua ban, qua ban
banh ve » ban ve, benh ve, anh ve
hanh ve » hanh vi, hanh va, hanh kem
cua tre » cua te, cuu tre, cua triet

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